Replacing a Mikuni Carburetor with a Weber Carburetor

[BJH324JH]

What do I need to do to replace the Mikuni carburetor to a Weber carburetor? I have a 1988 Mitsubishi Mighty Max 2.6l 4x4 manual transmission pick up truck.

UPDATE: 11:48 A.M. 6/16/2019 Sunday
I purchased the Weber 32/26 DGEV K610 carburetor from Carbs Unlimited and received it a few days later. Although, the carburetor has DGAV stamped on the base instead of what I believe is supposed to be DGEV. Anyone know why that is? I took multiple pictures of what you will get when you order the Weber 32/36 DGEV K610 carburetor.

I received this box that was in another box(inception ;):
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Overall contents of package:
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Contents laid out on table:
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Pictures taken of the carburetor body:
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UPDATE: 11:18 P.M. 8/11/2019 Sunday
The following pictures are the components you will receive with the k610 conversion kit. I took a picture of each component to show a closer view.

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The first three pictures were taken before the conversion started:
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These next pictures, I started removing...
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Carburetor removed with it's annoying vacuum hoses:
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Helpful Links:
Where I ordered the Weber 32/36 DGEV K610 Carburetor:
http://www.carburetion.com/Products/ProductDetails.aspx?Part=K610 (http://www.carburetion.com/Products/ProductDetails.aspx?Part=K610)

Weber 32/36 DGEV K610 Carburetor Diagram:
http://www.carburetion.com/diags/3236DGAVDiaginfo.asp

Identifying a Fake Weber Carburetor:
http://genuineweber.blogspot.com/

Redline Weber Contact Information:
http://www.redlineweber.com/contactus.html

What DGAV, DGEV, etc... means:
https://motofaction.org/mechanical-101/how-rebuild-clean-weber-32-36-dgv-dgav-dgev-dfv-dfev-dfav-carbs-carburetors-carburettors/how-identify-weber-model-differences/

[geezer101]

You'll need a K610 adapter kit and then decide what model Weber - either the 32/36 DGEV or the 38/38 DGES. There are intake manifold modifications you will also need to factor in (sealing the coolant port under the carb seat gasket and the coolant barb that normally runs to the Mikuni water choke). Delete the mechanical fuel pump on the head and install an electric pump by the fuel tank (a high volume/low pressure pump - check ebay, but I'd look at the Carbole 42S as it's good value for money and quieter than the Carter P4070 + more compact)

[BJH324JH]

You'll need a K610 adapter kit and then decide what model Weber - either the 32/36 DGEV or the 38/38 DGES. There are intake manifold modifications you will also need to factor in (sealing the coolant port under the carb seat gasket and the coolant barb that normally runs to the Mikuni water choke). Delete the mechanical fuel pump on the head and install an electric pump by the fuel tank (a high volume/low pressure pump - check ebay, but I'd look at the Carbole 42S as it's good value for money and quieter than the Carter P4070 + more compact)

Firstly, I want to thank you geezer for the help once again. You are much appreciated.

Second, what would be the difference between the Weber 32/36 DGEV or the 38/38 DGES? What would be the optimal choice for my vehicle?

[geezer101]

They are both 'good' - the 32/36 will be a big step up in both fuel economy and overall performance once you have it dialled in, but the 38 DGES will give you more top end and will be the option if you are planning on building a street engine. The 38 is a more modern designed carb and from what members have been saying it seems to be the carb Redline and other genuine product vendors have more of a tendency to recommend now.

[pennyman1]

FYI - the adaptor kit for the 38dges is different that the one for the 32/36 dges / dfav carbs - the 32/36 top plate is tapered for the 2 different barrels , vs the 38 is the same size on both ends.

[BJH324JH]

I think I'll be getting the 32/36 Weber because it seems that's the carburetor that most members here on the website convert to. I also have been doing a bit of research on these carburetors and unfortunately there is fakes floating around. Who sells genuine Weber carburetors? Now for the installation, what should I look forward to? What should I do to prepare the truck for conversion? Thank you guys for being patient with my questions.

[SubGothius]

Redline seems to be the main official Weber distributor in the US; others like Pierce Manifolds and Carbs Unlimited apparently resell Webers and related parts from Redline, though they may also sell an "economy" carb option that would be a clone to avoid. Main thing to look for is the Weber name, W logo, and "Made in Spain" cast into the body (not just a sticker) and the white/translucent electric choke-spring cover (clones have black choke covers, though I've seen secondhand apparently-genuine Webers retrofitted with black-covered clone electric chokes, e.g. if converted from a water choke). BTW, there's an eBay seller "userid[somelongnumber]" who may just be Pierce Manifolds; at least, I bought a linkage kit from them that wound up shipped by Pierce.

[geezer101]

Read this - http://www.mightyram50.net/vbulletin/showthread.php/2854-Thinking-about-buying-a-weber-carb-Becareful!!!!!!!!!!!!

[BJH324JH]

Is this the correct one for my truck?
https://www.ebay.com/itm/1979-1989-Mitsubishi-Dodge-Chrysler-2-0-2-6-M-T-32-36-Weber-Carb-Conversion-Kit/392072781155?hash=item5b495bdd63:g:9jIAAOSw7UZbMxn j
Seems to have everything ready for conversion.

[geezer101]

Yep it's a winner. Someone gave a review based on their efforts of installing it. That kit + an electric pump similar or the same as the one I recommended in my above post and you're almost ready to go. You'll need a fuel pump block off plate for the mechanical pump delete and spend a bit of time experimenting with the ignition tune to get it running nicely. The only thing I'm not super happy with is the open element air cleaner. It'll work, but getting a cool air charge from outside of the engine bay will optimise performance.

[BJH324JH]

Yep it's a winner. Someone gave a review based on their efforts of installing it. That kit + an electric pump similar or the same as the one I recommended in my above post and you're almost ready to go. You'll need a fuel pump block off plate for the mechanical pump delete and spend a bit of time experimenting with the ignition tune to get it running nicely. The only thing I'm not super happy with is the open element air cleaner. It'll work, but getting a cool air charge from outside of the engine bay will optimise performance.

Okay, I'll see if I can make a fuel pump cover out of aluminum for the cylinder head. As for the pump, I'll look into the one you stated before. What is the ignition tune? Is there examples of cool air charge you are talking about?

[geezer101]

The Weber is a vacuum beast - it will generate more vacuum than necessary to operate the vacuum advance on the distributor and as a result, will cause over advance. You'll have to play with the distributor in order to find a point where the engine won't experience pinging/knocking under acceleration.

As for the air cleaner, you can take a stock air cleaner box, cut the centre out of it where it mounted onto the Mikuni and make an adapter plate to suit the top of the Weber. You may need a spacer to lift the air cleaner up from the carb depending on if it fouls on anything. This sounds hard but all you need to really do is make a hole in a piece of cardboard that fits around the intake on the top of the carb (trace the hole from the top gasket in the kit), cut a round hole in the bottom of the air cleaner box, sit it on top of the carb where the mounting studs normally hold it in place, trace the hole onto the cardboard and use the cardboard as the template for your adapter (4mm thick alloy plate would be ok) and make some alignment marks so you don't goof when you put it together. The hardest part of this is making a bracket where the air cleaner cover can bolt down onto it as you won't have the stud like what's on the Mikuni to bolt it down. There is an adapter made for this job off the shelf if I recall.

Cut the alloy plate and drill some holes through the air cleaner base into the adapter plate. A bead of silicon and some rivets - done! Looks stock and has the cold air charge from the factory ducting (if you lengthen it and direct it out of the engine bay it will add torque)

[geezer101]

*I haven't looked for this on any of the tips/threads but there is bound to be pics and info from a member. Anyone got a link?

[85Ram50]

I did the mod on the OE air cleaner box and posted about it on here. I also posted some pics and comments about putting in a new Weber. IDK if that will help I just signed in to say there is an adapter for the airbox to Weber mount which will save you lots of aggravation. It is not as easy as Geez thinks. The OE hole for the Mikuni is a cone tapered down an inch or so, that you have to make cuts and hammer flat before cutting the hole then you will have to figure out how to make it airtight. I used a bunch of cork to fill the gap where the adapter will go and coated the cork in red gasket sealer. If I'd have known about the adapter that is what I would have done.

Found a couple adapters https://www.ebay.com/itm/LC-Engineering-1033030-Weber-32-36-38-Carb-to-K-N-Air-Filter-Air-Cleaner/272658882253?hash=item3f7bbc5ecd:g:hEMAAOSwQYZWxj6 R https://www.ebay.com/itm/WEBER-32-36-DGV-AIR-FILTER-ADAPTER-TO-5-1-4-AIR-CLEANER-WEBER-38-38-NEW/272527062295?hash=item3f73e0f517:g:AIoAAOSwblZZJHk R



(https://www.ebay.com/itm/WEBER-32-36-DGV-AIR-FILTER-ADAPTER-TO-5-1-4-AIR-CLEANER-WEBER-38-38-NEW/272527062295?hash=item3f73e0f517:g:AIoAAOSwblZZJHk R)

[geezer101]

Got a feeling this is the one - https://www.ebay.com/itm/SUZUKI-SAMURAI-AIR-FILTER-ADAPTER-WEBER-32-36-DGEV-99010-600-WEBER-38-38/361750857302?hash=item543a080656:g:K3kAAOSwzaJX7Yj b

[pennyman1]

That is the one to use - also listed for a Toyota air cleaner...

[85Ram50]

FF just crashed while I was uploading pics!
OK I put in a new spacer so I took pics while I had it off. You can see I used the base plate from that joke square air cleaner as a washer. I had to get longer hex bolts. You can see the cork I coated in gasket sealer. I got some squares of cork at Joanne Fabrics. It was one package. I also used JB Weld to seal the cuts I had to make to get it to hammer flat. Ditto the hole in the top for the post.
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Oh yea I had to put a hex bolt into that hole on the left in pic 1. Sorry do not remember the size.

[BJH324JH]

I called the Weber contact support to make sure the k610 was the proper kit for my truck. He confirmed it was. While I was on the phone with him, I took the opportunity to ask him some technical questions. My first question I asked him was if I needed an electric gas pump. He said no and that the mechanical fuel pump was good. I just need a regulator. He said the Weber only requires 2 1/2 to 3 1/2 psi. Second question was about the air filter housing. He said he never got a complaint about the rectangular styled air filter. Do you guys agree with the Weber contact support guy? If not can you please explain why?

[geezer101]

#1 - Putting a pressure regulator on the mechanical fuel pump beats the crap out of them and can lead to pump failure. Some guys have got away with it but most will opt for deleting the mechanical pump and installing an electric unit. Added bonus is being able to either fit a safety cut off switch or concealing a disable switch so if some A-hole steals your truck, it won't run for long.

#2 - open air filters. Bad. Pulling hot air into an air intake robs an engine of torque and impacts fuel economy (not just these trucks but any combustion engine). The exceptionally short air intake created by a direct mounted air filter is awesome for throttle response but again impacts on low down engine torque. The car manufacturers use a specific volume air intake design and length as a compromise for a high volume production vehicle (middle of the road torque, throttle response and fuel economy). Ever noticed that the vast majority of old school engine have literally the same design air cleaner assemblies?

The Weber is a big jump over the Mikuni 32/35 DIDTA style carb. You'll notice the difference straight away once you have it adjusted and tuned. The open element filter bolted to it won't appear to 'nerf' performance until you build a ducted intake and run it on a hot day. It will also shut up the intake hiss you'll get constantly as well. It's novel for a while but there will be a point where it'll drive you bananas...

[geezer101]

And for one of the great mysteries you made an inquiry about - the DGAV vs DGEV. The 'A' refers to 'aqua' (water choke) and the 'E' is electric. This particular carb is one of the times where the part designation makes sense - 'D' dual, 'G' gradual/progressive throttle, 'E/A' choke designation electric/water but the V is a bit ambiguous (might be throttle linkage orientation as there are a few different throttle layouts)

[BJH324JH]

#1 - Putting a pressure regulator on the mechanical fuel pump beats the crap out of them and can lead to pump failure. Some guys have got away with it but most will opt for deleting the mechanical pump and installing an electric unit. Added bonus is being able to either fit a safety cut off switch or concealing a disable switch so if some A-hole steals your truck, it won't run for long.

#2 - open air filters. Bad. Pulling hot air into an air intake robs an engine of torque and impacts fuel economy (not just these trucks but any combustion engine). The exceptionally short air intake created by a direct mounted air filter is awesome for throttle response but again impacts on low down engine torque. The car manufacturers use a specific volume air intake design and length as a compromise for a high volume production vehicle (middle of the road torque, throttle response and fuel economy). Ever noticed that the vast majority of old school engine have literally the same design air cleaner assemblies?

The Weber is a big jump over the Mikuni 32/35 DIDTA style carb. You'll notice the difference straight away once you have it adjusted and tuned. The open element filter bolted to it won't appear to 'nerf' performance until you build a ducted intake and run it on a hot day. It will also shut up the intake hiss you'll get constantly as well. It's novel for a while but there will be a point where it'll drive you bananas...

Excellent reply. I will go with your suggestions. Should I take into consideration the fuel filter? Like do I keep the old system or get a new system? Also I don't feel comfortable with a plastic fuel pump. Is there a metal alternative?

[geezer101]

The stock fuel filters work fine. The drop in fuel pressure passing through it won't affect anything but you'll need a filter before the pump to protect it from any debris that could be picked up straight from the tank (the pump should be mounted as close to the fuel tank as possible) As far as I know there aren't any plastic fuel pump assemblies but the mechanisms will have some kind of plastic casing (reduces corrosion risks and impact damage etc). You can use the Carter P0407 (I am not a fan of these 'rotary' style pumps - they're expensive, noisy and I had one fail spectacularly which ended up clogging a fuel filter with brass) or something like the Carbole 42S pump I've recommended from ebay on a number of different posts. Same pump as the Mr Gasket 42S but a third of the price (same pump right down to the part # on the pump housing/body)

[BJH324JH]

The stock fuel filters work fine. The drop in fuel pressure passing through it won't affect anything but you'll need a filter before the pump to protect it from any debris that could be picked up straight from the tank (the pump should be mounted as close to the fuel tank as possible) As far as I know there aren't any plastic fuel pump assemblies but the mechanisms will have some kind of plastic casing (reduces corrosion risks and impact damage etc). You can use the Carter P0407 (I am not a fan of these 'rotary' style pumps - they're expensive, noisy and I had one fail spectacularly which ended up clogging a fuel filter with brass) or something like the Carbole 42S pump I've recommended from ebay on a number of different posts. Same pump as the Mr Gasket 42S but a third of the price (same pump right down to the part # on the pump housing/body)

I am a bit hesitant about buying the carbole 42s as that has mixed reviews. It seems like you have to get lucky to get a good one.

[geezer101]

I am a bit hesitant about buying the carbole 42s as that has mixed reviews. It seems like you have to get lucky to get a good one.

Yeah, I've noticed they are hit and miss. But then you don't know how the people who've bought them have installed them and not everyone is either going to know or admit they screwed up mounting them.

[BJH324JH]

Yeah, I've noticed they are hit and miss. But then you don't know how the people who've bought them have installed them and not everyone is either going to know or admit they screwed up mounting them.

Yup, true. I guess I'll gamble. Maybe I can machine a stainless steel casing and get rid of the plastic casing.

[geezer101]

Yup, true. I guess I'll gamble. Maybe I can machine a stainless steel casing and get rid of the plastic casing.

Don't. The plastic housing does a few jobs as mentioned and the pump is either cast into it or pressed in. Worst case scenario you could make a protective housing so it doesn't get dirt etc on it. Cutting it apart presents risks. They are pretty cheap to buy but kind of pointless if you butcher one or 2 while making modifications (just an opinion...)

[BJH324JH]

Don't. The plastic housing does a few jobs as mentioned and the pump is either cast into it or pressed in. Worst case scenario you could make a protective housing so it doesn't get dirt etc on it. Cutting it apart presents risks. They are pretty cheap to buy but kind of pointless if you butcher one or 2 while making modifications (just an opinion...)

I guess if all the bad reviews were right about this pump being garbage, I'll take the opportunity to upgrade it. :)

Does anyone know what connections get blocked off and removed from the intake manifold? I took a picture with everything still attached to it. Someone please edit the picture in an image editing program, like in paint and circle what needs to be removed or blocked. Thank you.

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More close up pictures of the intake manifold with it's various components attached to it.

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[geezer101]

You can either remove the EGR valve solenoid and fit a blanking plate over it (easy to make) or just leave it in place with the vac hoses disconnected. The Christmas tree vacuum barb on the manifold needs to be removed and a threaded bung screwed into there. The water barb connection for the heater return and carb choke should be removed and a single upright barb installed (the original barb will most likely be paper thin from rust anyway) The rest of the vacuum connections are only vac thermo switches and pose no risk to vacuum leaks but you could delete them for appearances sake.

I went a little nuts with mine and completely cut off the EGR gallery running around the manifold plenum and sculpted the manifold. Mine was easier to do as it was off a Gen1 G63B and didn't have a lot of emissions control ancillaries on it and didn't have jet valves either (I had to prepare the manifold for repairs anyway as the water jacket cover plate under the plenum had corroded out and had a few pin holes in it). I capped off the gas gallery that runs through the head into that EGR gallery and ran a metric thread tap through the coolant port that is located on the carb mounting face/seat and installed a grub screw in there to seal it off. Not entirely necessary but reduces the risk of coolant somehow backing up into the plenum if the carb install kit manages to develop a leak.

[BJH324JH]

You can either remove the EGR valve solenoid and fit a blanking plate over it (easy to make) or just leave it in place with the vac hoses disconnected. The Christmas tree vacuum barb on the manifold needs to be removed and a threaded bung screwed into there. The water barb connection for the heater return and carb choke should be removed and a single upright barb installed (the original barb will most likely be paper thin from rust anyway) The rest of the vacuum connections are only vac thermo switches and pose no risk to vacuum leaks but you could delete them for appearances sake.

I went a little nuts with mine and completely cut off the EGR gallery running around the manifold plenum and sculpted the manifold. Mine was easier to do as it was off a Gen1 G63B and didn't have a lot of emissions control ancillaries on it and didn't have jet valves either (I had to prepare the manifold for repairs anyway as the water jacket cover plate under the plenum had corroded out and had a few pin holes in it). I capped off the gas gallery that runs through the head into that EGR gallery and ran a metric thread tap through the coolant port that is located on the carb mounting face/seat and installed a grub screw in there to seal it off. Not entirely necessary but reduces the risk of coolant somehow backing up into the plenum if the carb install kit manages to develop a leak.

Okay, like this right? Am I missing something?:
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[geezer101]

Nope. Nailed it :thumbup: There is quite a considerable difference in the intake runner length between the early and the updated intake manifolds. Wonder if there was much of a difference in overall torque as a result...

[BJH324JH]

Nope. Nailed it :thumbup: There is quite a considerable difference in the intake runner length between the early and the updated intake manifolds. Wonder if there was much of a difference in overall torque as a result...

Thank you, I wonder though, isn't some of the sensors on the intake manifold used to measure the engine temperature? Check this out: https://www.rockauto.com/en/catalog/mitsubishi,1988,mighty+max,2.6l+l4,1206683,cooling +system,temperature+sender+/+sensor,4748

The sensor looks quite identical to the picture I posted above. I suppose things did change a bit from the 1st gen.

[geezer101]

I'm mot 100% sure which of the sensors in the thermostat housing does what as there is at least one that is connected to the feedback system on Gen 2's. It would be the ideal place to hook up an aftermarket temp gauge and the sensors seem to be inexpensive. OOC - you got any aftermarket gauges set up in your truck?

[BJH324JH]

I'm mot 100% sure which of the sensors in the thermostat housing does what as there is at least one that is connected to the feedback system on Gen 2's. It would be the ideal place to hook up an aftermarket temp gauge and the sensors seem to be inexpensive. OOC - you got any aftermarket gauges set up in your truck?
I don't have aftermarket gauges installed.

[geezer101]

If your engine had an O2 sensor in the exhaust, this is by far the best thing to help adjust your carb and get it running nicely by installing an A/F ratio meter. Add maybe a vacuum gauge and oil pressure as well and you'll know when something is running right or wrong.

[BJH324JH]

If your engine had an O2 sensor in the exhaust, this is by far the best thing to help adjust your carb and get it running nicely by installing an A/F ratio meter. Add maybe a vacuum gauge and oil pressure as well and you'll know when something is running right or wrong.

I'll think about it. Money is going out faster than I can bring it in. I'm going to let the piggy bank rest a while before I make more investments towards my truck. For now, I just need it running.

[geezer101]

I'll think about it. Money is going out faster than I can bring it in. I'm going to let the piggy bank rest a while before I make more investments towards my truck. For now, I just need it running.

I hear ya. I've kept my 'bargain hound' mode on the entire time I've been collecting stuff for my truck. Now I need free time to glue everything together, never seem to have both time and cash...

[BJH324JH]

I hear ya. I've kept my 'bargain hound' mode on the entire time I've been collecting stuff for my truck. Now I need free time to glue everything together, never seem to have both time and cash...

I completely get what you mean about time and cash. Two things that we have to carefully manage.

I will definitely try my best to keep you and everyone else that has been helping me through this conversion updated. I owe every helpful member here a big hug and can't express how grateful I am to have members like Geezer, who take their precious time to help people in need. Thank you everyone who has helped me and thank you Camiot for keeping this website alive.

[SubGothius]

FWIW re: electric pumps, I've long been a fan of the Carter P90091 (and the P60504 and P76438 it superseded) for use with Weber carbs requiring low fuel pressure -- quiet, compact and reliable, and its gerotor pump mechanism provides a smooth, continuous flow, unlike solenoid piston-driven designs. Maybe this tip comes a bit late if you already bought yours, but at least of benefit to others playing along here.

[noahwins]

Yet another option is finding a fuel injected tank (MY 1990+) and using this pump:

https://fuelsafe.com/fplp/

You get the longevity and quiet operation of a liquid cooled pump but they're costly.

The Carter pumps are sturdy and reliable (I learned from a Datsun guy they use them to pump and cool differential coolers on 510s and Zs) but I thought they were a little noisy for my tastes. We used Airtex pumps at the restoration shop I worked at. FWIW.

[geezer101]

Holy crap - $220+ for a fuel pump!?!! I bet they'd be good for that price though...

[BJH324JH]

Yet another option is finding a fuel injected tank (MY 1990+) and using this pump:

https://fuelsafe.com/fplp/

You get the longevity and quiet operation of a liquid cooled pump but they're costly.

The Carter pumps are sturdy and reliable (I learned from a Datsun guy they use them to pump and cool differential coolers on 510s and Zs) but I thought they were a little noisy for my tastes. We used Airtex pumps at the restoration shop I worked at. FWIW.


FWIW re: electric pumps, I've long been a fan of the Carter P90091 (and the P60504 and P76438 it superseded) for use with Weber carbs requiring low fuel pressure -- quiet, compact and reliable, and its gerotor pump mechanism provides a smooth, continuous flow, unlike solenoid piston-driven designs. Maybe this tip comes a bit late if you already bought yours, but at least of benefit to others playing along here.


Thank you for the suggestions, I will consider them. I have not yet gotten an electric fuel pump, but am doing my best to find a good one. I appreciate the suggestions. I didn't know I had new replies to this thread, sorry for the late reply.

[BJH324JH]

I'm a bit perplexed as to where the last few parts of the carburetor kit go. These are the parts in question:
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23117&d=1565591692&thumb=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23113&d=1565591616&thumb=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23109&d=1565591538&thumb=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23116&d=1565591677&thumb=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23112&d=1565591595&thumb=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23106&d=1565591324&thumb=1

The 8mm aluminium barb as per the instructions is ment to block the water choke hose. Although as suggested by geezer, I replaced it with a straight fitting that I machined out of aluminium, thus eliminating the need for the 8mm aluminium barb. Seeing as the weber instructions that came with the carburetor kit didn't have pictures, I am questioning if this is the water choke they are referring to in the instructions:
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23115&d=1565591646&thumb=123156

[85Ram50]

Spare Parts? I had a lot of them. That boomerang looking bit gets bolted to the top pf the valve cover for the gas cable to mount to.The two big holes are for existing bolts and the little one is for the clip on the cable.

[geezer101]

The barb you have marked in your pic is the water choke feed described by the Weber instructions. There are parts for a lot of different combinations of install. The bracket is the throttle cable retainer (as 85Ram50 has pointed out). The hose clamps are for fuel hoses. The spring is a throttle return (of some sort...) and the odd bolts and small elongated plate... I got nothing on that :shrug: The vacuum caps are for the superfluous vacuum connections.

[BJH324JH]

The barb you have marked in your pic is the water choke feed described by the Weber instructions. There are parts for a lot of different combinations of install. The bracket is the throttle cable retainer (as 85Ram50 has pointed out). The hose clamps are for fuel hoses. The spring is a throttle return (of some sort...) and the odd bolts and small elongated plate... I got nothing on that :shrug: The vacuum caps are for the superfluous vacuum connections.

I'll just save them, just in case they are needed or someone needs them. There are two vacuum hose connections on the distributor, which one do I plug and which one do I use?
23165

Does the distributor hose connect to this connection on the carburetor:
23164

[geezer101]

Ok, you've got one of those distributors... not sure on which vac barb to cap on that one. I'm pretty sure the circled hose barb on the Weber is the correct location to hook up the distributor advance. Vac advance has to be connected from a source above the throttle butterflies or it'll pull continuous vacuum.

[Buckbent]

So am I throwing my money away going with this replacement? https://www.autozone.com/fuel-delivery/carburetor/united-carburetors-carburetor-urc-cr280/485266_446615_6626_2425 cause my carb is dumping fuel and flooding

[geezer101]

So am I throwing my money away going with this replacement? https://www.autozone.com/fuel-delivery/carburetor/united-carburetors-carburetor-urc-cr280/485266_446615_6626_2425 cause my carb is dumping fuel and flooding

Not necessarily 'throwing' money away but the stock carbs aren't cheap. This is a simple 'just swap it and you're done' deal - no installing electric fuel pumps, no extra wiring, no coolant line deletes (this particular Mikuni variant has an electric choke anyway so make sure it matches the carb you're replacing) and also no messing with rebuild kits (if carbs aren't a thing you're comfortable stripping down, this isn't the place to start)
BUT for the same amount of money, you can swap up to a simpler carb that has vastly improved all round performance - not just HP and torque but fuel economy as well. There is some work in installing a Weber but the rewards are worth it, plus there is a ton of info on how to do it, where to get a genuine unit and how to trouble shoot it so it'll run right.

[StarquestMan]

I'll just save them, just in case they are needed or someone needs them. There are two vacuum hose connections on the distributor, which one do I plug and which one do I use?
23165

Does the distributor hose connect to this connection on the carburetor:
23164

If memory serves right on the dual vacuum advance units used for Federal High Altitude converted vehicles and California emissions trucks the top port is a secondary advance for the "high altitude compensator" that advances the timing by 5 degrees and the bottom one is the main vacuum advance that is used by the carburetor. hope this helps

[geezer101]

I learned sumpin' there from Starquest. I wonder if it's worth experimenting with the dual vacuum solenoid on the distributor by trying each one individually with the Weber? Reasoning behind it is the Weber is a vacuum beast and has a tendency to over advance unmodified distributors, possibly causing detonation :think:

[BJH324JH]

If memory serves right on the dual vacuum advance units used for Federal High Altitude converted vehicles and California emissions trucks the top port is a secondary advance for the "high altitude compensator" that advances the timing by 5 degrees and the bottom one is the main vacuum advance that is used by the carburetor. hope this helps

I will try the lower distributor barb and hope that is the correct one. Thank you btw. If anyone knows for sure if the lower barb on the distributor should be used for the weber, please confirm.

[StarquestMan]

Ill check my service manual tomorrow but i'm 95% sure that's how its set up. Geezer has a good point about trying them both though since the high altitude advance may have less advancement than the main lower section of the unit.

[StarquestMan]

Ok i checked the FSM and it does in fact use the top port for the HAC system and the bottom for regular vacuum advance. i couldn't confirm though that the top port advances timing by a set 5 degrees like i thought though. i'm assuming that the main vacuum advance will give more adjustment range than the top section would but like geezer101 said if the Weber does provide more vacuum then you will need to account for that. in fact im curios myself on what the best solution is since i may be using a Weber myself on my Mighty Max 4x4 that has a California emissions setup?

[BJH324JH]

Ok i checked the FSM and it does in fact use the top port for the HAC system and the bottom for regular vacuum advance. i couldn't confirm though that the top port advances timing by a set 5 degrees like i thought though. i'm assuming that the main vacuum advance will give more adjustment range than the top section would but like geezer101 said if the Weber does provide more vacuum then you will need to account for that. in fact im curios myself on what the best solution is since i may be using a Weber myself on my Mighty Max 4x4 that has a California emissions setup?

Thank you very much.

[SubGothius]

I gather from other threads here, our vacuum advance should be fed from the left (slightly higher) vacuum barb on the Weber carb, the one normally blocked with a screw in the end, as the usual vac advance barb on the right gives too much vacuum too early.

[BJH324JH]

I just got the electric gas pump and was wondering how you wire this thing up? There is a wire coming out of the electirc gas pump with a label on the cord that says "to ground only", "do not wire to positive."
23215
23216
23220

Also, how do I wire the electric choke?

[85Ram50]

BJH324JH
Look at post #37 It should all be the same even though you have a different pump. It is still two wires power and ground. The part about T'ing off an existing wire will help and the electric choke on mine is wired to the coil. Same pin the wire from the distributor connects to.
http://www.mightyram50.net/vbulletin/showthread.php/6738-fuel-pump-questions-Weber-conversion?p=69074#post69074

[geezer101]

Ground goes to the shortest path it can on the body/chassis of the truck (requires a good, solid connection). The electric choke is simply live power with the ignition on (like the coil or distributor as 85Ram has indicated). As mentioned, it's the same wire as the fuel cut solenoid on the factory Mikuni carb just repurposed.

[claych]

.....

[claych]

What do I need to do to replace the Mikuni carburetor to a Weber carburetor? I have a 1988 Mitsubishi Mighty Max 2.6l 4x4 manual transmission pick up truck.

UPDATE: 11:48 A.M. 6/16/2019 Sunday
I purchased the Weber 32/26 DGEV K610 carburetor from Carbs Unlimited and received it a few days later. Although, the carburetor has DGAV stamped on the base instead of what I believe is supposed to be DGEV. Anyone know why that is? I took multiple pictures of what you will get when you order the Weber 32/36 DGEV K610 carburetor.

I received this box that was in another box(inception ;):
22818

Overall contents of package:
22819
Contents laid out on table:
22820

Pictures taken of the carburetor body:
228242282622827
228282282922830
228312283222833
22834

UPDATE: 11:18 P.M. 8/11/2019 Sunday
The following pictures are the components you will receive with the k610 conversion kit. I took a picture of each component to show a closer view.

23103 23104231052310623107231082310923110231112311223113 23114231152311623117231182311923120231212312223127 23123231242312523126

The first three pictures were taken before the conversion started:
23128 2312923130

These next pictures, I started removing...
23131231322313323134231352313623137231382313923140 23141231422314323144231452314723148231492315023151 23152

Carburetor removed with it's annoying vacuum hoses:
23146

Helpful Links:
Where I ordered the Weber 32/36 DGEV K610 Carburetor:
http://www.carburetion.com/Products/ProductDetails.aspx?Part=K610 (http://www.carburetion.com/Products/ProductDetails.aspx?Part=K610)

Weber 32/36 DGEV K610 Carburetor Diagram:
http://www.carburetion.com/diags/3236DGAVDiaginfo.asp

Identifying a Fake Weber Carburetor:
http://genuineweber.blogspot.com/

Redline Weber Contact Information:
http://www.redlineweber.com/contactus.html

What DGAV, DGEV, etc... means:
https://motofaction.org/mechanical-101/how-rebuild-clean-weber-32-36-dgv-dgav-dgev-dfv-dfev-dfav-carbs-carburetors-carburettors/how-identify-weber-model-differences/

I call bullshit !!! where is the picture of the weber mounted to the intake manifold???? & running. (http://www.mightyram50.net/vbulletin/member.php/2931-BJH324JH)

[BJH324JH]

BJH324JH
Look at post #37 It should all be the same even though you have a different pump. It is still two wires power and ground. The part about T'ing off an existing wire will help and the electric choke on mine is wired to the coil. Same pin the wire from the distributor connects to.
http://www.mightyram50.net/vbulletin/showthread.php/6738-fuel-pump-questions-Weber-conversion?p=69074#post69074


Ground goes to the shortest path it can on the body/chassis of the truck (requires a good, solid connection). The electric choke is simply live power with the ignition on (like the coil or distributor as 85Ram has indicated). As mentioned, it's the same wire as the fuel cut solenoid on the factory Mikuni carb just repurposed.

Thank you guys for the help.

[BJH324JH]

I call bullshit !!! where is the picture of the weber mounted to the intake manifold???? & running. (http://www.mightyram50.net/vbulletin/member.php/2931-BJH324JH)

I'm trying to make time for the truck, it's just that life throws things my way that I have to deal with first. I have yet to install the fuel pump due to trying to keep a roof over my head. As soon as I free up time, I will get back to trying to get the truck in working order. I will also take pictures of the new Weber on the intake manifold. I am not B.S. anyone.

[geezer101]

LOL don't sweat it. Life is what happens while you're making other plans. Hell, my trucks been off the road for this long. I'm still scrounging parts for it... I either have time but no money or too busy to direct my attention to it. You're a lot closer to having your truck running than I do atm.

[BJH324JH]

LOL don't sweat it. Life is what happens while you're making other plans. Hell, my trucks been off the road for this long. I'm still scrounging parts for it... I either have time but no money or too busy to direct my attention to it. You're a lot closer to having your truck running than I do atm.

Thank you for understanding geezer101.

[85Ram50]

Got a feeling this is the one - https://www.ebay.com/itm/SUZUKI-SAMURAI-AIR-FILTER-ADAPTER-WEBER-32-36-DGEV-99010-600-WEBER-38-38/361750857302?hash=item543a080656:g:K3kAAOSwzaJX7Yj b

I see how it would mount to the carb. I do not see how the air cleaner would be attached to it. I can infer that long bolt might be meant for the center hole to hold the top down, and by that the whole housing, Is that the case?

[85Ram50]

EDIT 5-22-20 - This did not work. It bolts on fine and has a center pin but it is too high and doesn't allow the OE air box to sit on it properly plus its like 3 inches above the studs it is supposed to bolt down on the valve cover.

I ended up ordering this https://www.ebay.com/itm/Toyota-Air-Filter-Adapter-20R-for-Weber-Carburetor-32-36-DGEV-or-38-DGAS-/400796653831
(https://www.ebay.com/itm/Toyota-Air-Filter-Adapter-20R-for-Weber-Carburetor-32-36-DGEV-or-38-DGAS-/400796653831)

[BJH324JH]

I finally have a bit of free time to work on the truck. I had some questions regarding the fuel hoses though. There is two fuel hoses as you can see in the following picture:
23393
What do I do with them? I know one connects to the carburetor, but what about the other one. Also, which fuel hose connects to the carburetor? One is skinner than the other.

[85Ram50]

None of that looks familiar to me but I know on the first gen there is a fuel return line from the OE pump. Look at the fuel system diagram in the manual it should tell you. When I added the electric pump I blocked off the hard fuel return line with a silicon cap in the engine bay where the hose from the pump connected to it.

[BJH324JH]

BJH324JH
Look at post #37 It should all be the same even though you have a different pump. It is still two wires power and ground. The part about T'ing off an existing wire will help and the electric choke on mine is wired to the coil. Same pin the wire from the distributor connects to.
http://www.mightyram50.net/vbulletin/showthread.php/6738-fuel-pump-questions-Weber-conversion?p=69074#post69074

I was wondering, will the Duralast Oil Pressure Switch PS122 work on my gen 2 Mitsubishi MM?

[BJH324JH]

Ground goes to the shortest path it can on the body/chassis of the truck (requires a good, solid connection). The electric choke is simply live power with the ignition on (like the coil or distributor as 85Ram has indicated). As mentioned, it's the same wire as the fuel cut solenoid on the factory Mikuni carb just repurposed.

Geezer101, I wonder why do you need the shortest path for ground?

[BJH324JH]

[QUOTE=geezer101;69384]Ground goes to the shortest path it can on the body/chassis of the truck (requires a good, solid connection). The electric choke is simply live power with the ignition on (like the coil or distributor as 85Ram has indicated). As mentioned, it's the same wire as the fuel cut solenoid on the factory Mikuni

Also how do you know if you grounded it properly?

[geezer101]

[QUOTE=geezer101;69384]Ground goes to the shortest path it can on the body/chassis of the truck (requires a good, solid connection). The electric choke is simply live power with the ignition on (like the coil or distributor as 85Ram has indicated). As mentioned, it's the same wire as the fuel cut solenoid on the factory Mikuni

Also how do you know if you grounded it properly?

A long ground lead is unnecessary as you will (more than likely) mounting the pump to the chassis and by keeping it short you reduce the risk of it failing (running a long ground lead will create resistance = drop in current. The fuel pump might struggle to work at it's optimal capacity...) Testing it - either live (the positive 12v power from the ignition circuit on to the point where you want to ground it to and check your voltage) or with a multimeter and check resistance from a bolt or bare metal and the ground point you're planning on using.

[85Ram50]

Also how do you know if you grounded it properly?

The only way I ever knew I had grounded properly was that the item worked. If it did not and I thought it was the ground I would check to be sure there was bare metal to metal contact. I did not have to do that with my fuel pump and I just used one of the bolts the mounting plate is bolted to the frame with for ground. Whatever bolt you are bolting the pump to the truck with will do fine for a ground spot as long as you are bolting to the frame.
On the Duralast oil pressure switch I don't see why it would not work, the thing is just a switch that cuts off when oil pressure fails.

[BJH324JH]

[QUOTE=BJH324JH;69966]

A long ground lead is unnecessary as you will (more than likely) mounting the pump to the chassis and by keeping it short you reduce the risk of it failing (running a long ground lead will create resistance = drop in current. The fuel pump might struggle to work at it's optimal capacity...) Testing it - either live (the positive 12v power from the ignition circuit on to the point where you want to ground it to and check your voltage) or with a multimeter and check resistance from a bolt or bare metal and the ground point you're planning on using.


The only way I ever knew I had grounded properly was that the item worked. If it did not and I thought it was the ground I would check to be sure there was bare metal to metal contact. I did not have to do that with my fuel pump and I just used one of the bolts the mounting plate is bolted to the frame with for ground. Whatever bolt you are bolting the pump to the truck with will do fine for a ground spot as long as you are bolting to the frame.
On the Duralast oil pressure switch I don't see why it would not work, the thing is just a switch that cuts off when oil pressure fails.

Thank you so much guys!

[BJH324JH]

Couldn't find t-fittings at my local auto parts store. So I machined one out of aluminium with my crappy tools. I hope it doesn't leak oil. Here are some pictures of the homemade t-fitting if you are interested:
233992340123400
23402

[BJH324JH]

So, I'm getting ready to mount the fuel pump to the truck frame, I'm just wondering before I do any of that, are the fuel filter hoses the ones you connect to the electric fuel pump?

23403

[85Ram50]

What I did, I think there is a picture of it at that link to post #37, is connect the outflow from the filter to the intake of the pump. Then the out from the pump to the hard line the outflow from the filter was connected to. The connection to the hard line is hidden in the pics I took. I also put in a new filter.

[geezer101]

Mount the pump as close as practical to the tank with the fuel filter installed between the tank and the pump. That way it screens the debris out of the fuel before it passes through the pump. Make sure the pump is shielded from getting hit by rocks and dirt etc.

[BJH324JH]

What I did, I think there is a picture of it at that link to post #37, is connect the outflow from the filter to the intake of the pump. Then the out from the pump to the hard line the outflow from the filter was connected to. The connection to the hard line is hidden in the pics I took. I also put in a new filter.

The filter has two fuel lines, which one is which?

[geezer101]

Check the filter - it should have fuel in/out marked on it. You will need to install the pump on the fuel out hose on the filter.

[85Ram50]

You can always trace the lines from under the rig to see where they go if there is no in/out marking on the filter. I cannot find a 2nd gen manual in the manuals section and I was lucky the filter for my rig is in on the bottom out at the top.

Edit- DUH, The line from the tank which is a very short distance will be the in line on the fuel filter.

[BJH324JH]

Check the filter - it should have fuel in/out marked on it. You will need to install the pump on the fuel out hose on the filter.

It unfortunately doesn't have markings. Checked all around the fuel filter and couldn't find the markings. Is it safe just by looking at it that the top hose on the fuel filter is the fuel coming in and the lower one is the outlet, where the fuel comes out after being filtered by the paper?

[geezer101]

You'll need to physically trace the fuel lines if there aren't any flow indicators on the filter. Guessing could be disastrous. The fuel pick up from the tank should be the easiest to identify.

[85Ram50]

It unfortunately doesn't have markings. Checked all around the fuel filter and couldn't find the markings. Is it safe just by looking at it that the top hose on the fuel filter is the fuel coming in and the lower one is the outlet, where the fuel comes out after being filtered by the paper?

The tank is right there, just check which line goes to the tank. That is the line into the fuel filter the other one will be going to the hard line that runs along the frame to the front. You disconnect that one from the hard line and attach it to the in line on the new pump. Connect the out line from the new pump to the hard line you just disconnected the fuel filter from.

[BJH324JH]

This is so perplexing! The airtex video demonstrated an oil pressure sensor with three terminals on it. The first terminal is power, that one is easy, it hooks up to the electric fuel pump.
The second terminal is for the starter solenoid that is powered up when the engine is cranked. Lastly, the third terminal is for ignition power. In guessing the last one is for a keyed ignition wire. What terminal on the starter do I wire the oil pressure sensor to? There is "S","B","M" terminals on the solenoid according to the manual. Here is a picture from the manual:
23409

The last terminal on the oil pressure sensor switch is for the ignition. I'm guessing a keyed terminal?

[85Ram50]

This is so perplexing! The airtex video demonstrated an oil pressure sensor with three terminals on it. The first terminal is power, that one is easy, it hooks up to the electric fuel pump.
The second terminal is for the starter solenoid that is powered up when the engine is cranked. Lastly, the third terminal is for ignition power. In guessing the last one is for a keyed ignition wire. What terminal on the starter do I wire the oil pressure sensor to? There is "S","B","M" terminals on the solenoid according to the manual. Here is a picture from the manual:
23409

The last terminal on the oil pressure sensor switch is for the ignition. I'm guessing a keyed terminal?
You have it. That link I posted explains what wires to connect to. You have to T splice the starter wire or I guess connect to the same post on the starter, and the other wire which is hot only when the key is on and supplies the power while running should be hanging loose since you removed the Mikuni. It powered the Mikuni shut off solenoid I think.

[geezer101]

^correct. The loose wire powered the fuel cut solenoid.

[SubGothius]

Connect the S(tart) terminal on the oil pressure safety switch to the S terminal on the solenoid.

Auto parts, hardware, or electrical supply stores should have a spade terminal adapter that has 1 female and 2 male spade connectors on it. The female end goes on the S terminal, then the male ends take your stock starter signal wire and the new wire to the safety switch.

(EDIT: These are apparently called "double male" terminals/adapters and come in "chair", "flat tab" and "piggy back" types -- Dorman part# 85412 (https://www.dormanproducts.com/p-27736-85412.aspx) comes with 2 of each for about $3 at Pep Boys (https://www.pepboys.com/dorman-conduct-tite-interior-adapter-assortment/product/8354147) or $2 at O'Reilly (https://www.oreillyauto.com/detail/b/dorman-conduct-tite-3354/lighting---electrical-16777/connectors-sockets-16631/universal-wire-connectors-25380/13d878ed189c/dorman-conduct-tite-quick-splice-terminal-assortment/85412/4176614). Or, you could find a piggyback crimp-on terminal for your safety-switch wire, which has a female spade connector with an extra male spade forking off of it for your starter signal wire.)

The way these safety switches typically work, there's an internal switch that flips whether the (P)ump terminal is connected to the (S)tart terminal or the (I)gnition terminal. At rest, P is connected to S, then oil pressure flips that to connect P to I instead. This can be handy to know in case the switch ever fails, as you can probably just swap the I wire over to the S terminal to get going again until you can replace the switch.

Ideally, you'll also want that P(pump) wire triggering a relay that sends power directly from the battery (+) terminal to the pump, rather than having power from the ignition switch go thru the safety switch directly to the pump.

[BJH324JH]

You'll need to physically trace the fuel lines if there aren't any flow indicators on the filter. Guessing could be disastrous. The fuel pick up from the tank should be the easiest to identify.


The tank is right there, just check which line goes to the tank. That is the line into the fuel filter the other one will be going to the hard line that runs along the frame to the front. You disconnect that one from the hard line and attach it to the in line on the new pump. Connect the out line from the new pump to the hard line you just disconnected the fuel filter from.

You guys are right. Guessing is not an option especially when the freaking tank is just right there in the open for me to see, like 85ram50 mentioned. I'll hunt the lines down.

[BJH324JH]

Connect the S(tart) terminal on the oil pressure safety switch to the S terminal on the solenoid.

Auto parts, hardware, or electrical supply stores should have a spade terminal adapter that has 1 female and 2 male spade connectors on it. The female end goes on the S terminal, then the male ends take your stock starter signal wire and the new wire to the safety switch.

The way these safety switches typically work, there's an internal switch that flips whether the (P)ump terminal is connected to the (S)tart terminal or the (I)gnition terminal. At rest, P is connected to S, then oil pressure flips that to connect P to I instead. This can be handy to know in case the switch ever fails, as you can probably just swap the I wire over to the S terminal to get going again until you can replace the switch.

Ideally, you'll also want that P(pump) wire triggering a relay that sends power directly from the battery (+) terminal to the pump, rather than having power from the ignition switch go thru the safety switch directly to the pump.

Thank you so much for clearing this up for me and educating me on how oil pressure sensors work. Also, thank for the tip about jumping the cables to get things working again. That may come in handy in a crappy situation.

I don't have the time to go to the auto parts store and get the spade terminal adapter you are talking about, so I just made one. Here is a picture of the one I made:
23437

As for having this setup ideally, what extra electronics would I have to buy. You mentioned a relay, is there something specific you can point me too. I don't even know what the heck a relay is and how I would wire it to the truck.

So far, the "P" (Power) terminal is hooked up and "S" (Starter Solenoid) are hooked up. I just need the "I" (Ignition) terminal hooked up. Everyone says to hook it up to the existing fuel cut off solenoid that's hanging around in the truck. Although there is other connections hanging around as well. Here is a picture of all the connections hanging around. Which one do I tap into?
23438

[85Ram50]

Do you remember which one you disconnected from the Mikuni cut off solenoid? Just directly connect to the end of it.
if not on my first gen trace the yellow with red stripe wire that connects to the temp sensor back to the harness. there are two black wires coming out at the same spot. One goes to the starter the other one goes to the Mikuni and now to my oil pressure cut off switch.

[geezer101]

Here's a ready made kit - https://www.ebay.com/itm/40A-12V-Wiring-Harness-Kit-With-Switch-And-Relay-LED-Light-Bar-Off-Road-Truck/151883385139?hash=item235cf48933:g:lkoAAOSwCU1Y1D5 7

Take the chintzy switch out of the equation and you have a fused 40 amp rated relay with most of the wiring to hook it up :thumbup:

[85Ram50]

BJH324JH- Once you figure out how to wire that relay up let me know I'd put one in if I knew how to do it right :)

[BJH324JH]

BJH324JH- Once you figure out how to wire that relay up let me know I'd put one in if I knew how to do it right :)

I am a complete beginner at this and can barely do the oil switch method. I might try geezers method, but I already started on the oil pressure switch method and want to finish it. Maybe in the future I'll give geezers relay method a try, but I'm already close to finishing. Anyways what's the advantage of using the ready made kit over using the chintzy oil pressure switch?

Now as for the last wire mentioned, I can't for the life of me figure out where the fuel cut off solenoid wire is to hook up! May anyone with a 2nd generation MM help me get this damn thing wired up already. Just out of curiosity, does the oil pressure sensor switch use "Accessory" power, or "On" power? Also, does the weber choke use "Accessory" power, or "On" power? Sorry guys for being such a freaking idiot, but I really do like doing this and wish to learn.

[85Ram50]

Now I feel terrible for having to tell you that apparently the best install of the electric pump includes the oil cut off and a relay. As I understand it the oil cut off won't shut down the pump if the motor did not stop running in a rollover crash making things quite dicey if you are trapped. If I understand correctly the relay takes care of that factor. IDK how.

If you do not remember which wire you took off the Mikuni ??? How many loose wires do you have? What connectors are on the end? What sort of connector does the Mikuni have on it that might receive one of those wire connectors? Maybe Pennyman1 or Geezer101 will stop by.

[BJH324JH]

Now I feel terrible for having to tell you that apparently the best install of the electric pump includes the oil cut off and a relay. As I understand it the oil cut off won't shut down the pump if the motor did not stop running in a rollover crash making things quite dicey if you are trapped. If I understand correctly the relay takes care of that factor. IDK how.

If you do not remember which wire you took off the Mikuni ??? How many loose wires do you have? What connectors are on the end? What sort of connector does the Mikuni have on it that might receive one of those wire connectors? Maybe Pennyman1 or Geezer101 will stop by.

If you take a look at post #90, I took a picture of all the connections. I've just been at this on and off and forgot where things went.

[85Ram50]

I see two wires. The temp sensor wire on mine is in front of the intake manifold before the distributor.
Anyway, if you just have those two wires with different connectors on them go look at the Mikuni you removed for where one of them might fit.

[SubGothius]

For power to the I terminal, you can see if any of those loose connectors have ~12V power when the key is on and not when it's off. If your Mikuni setup is like my '87, the fuel cutoff solenoid terminals are bundled into that multi-terminal connector block. You may wish to just cannibalize the old carb side of that connector, cut the wire pair at the cutoff solenoid, and splice onto that; one of those wires should get 12V switched current, and the other is a ground. You can tell which gizmo is the solenoid when you plug it in and turn the key, you should hear it click.

A relay is a switch in one circuit that's operated by electricity in another circuit. You want a NO SPST type (normally-open single-pole single-throw), which has 4 or 5 terminals: two operate the internal switch, which dis/connects power across the other two, or some NO SPST relays have an extra switched output terminal (called a "dual make" relay). When power flows across the control terminals, that energizes an internal electromagnet that closes a switch across the switched terminals.

Why use a relay? The electromagnet draws tiny current, whereas the switch can handle high current, so you can switch a high-current circuit with another one that's low-current, dodgy/unknown, or otherwise worth protecting. The circuit across the ignition key switch to the I and then P terminals may not be strong enough to drive the pump, or you may just want to protect your ignition switch and pressure safety switch by reducing the current demand across them, so we use that circuit to operate the relay, which in turn switches current directly from the battery (+) terminal to the pump.

This page explains and illustrates more about relays:
https://www.the12volt.com/relays/spdt-and-spst-automotive-relays.asp

Here's the basic wiring you'll use:
https://www.the12volt.com/relays/relaydiagram47.html

...where terminal 86 will take the 12V wire from your old cutoff solenoid , 85 will take the old solenoid (or any) ground, 30 will take a fused line from the battery (+) terminal, and 87 will go to the pump. If you get a dual-make relay with an 87b terminal, that allows for another trick you can do in a pinch: swap the wire from the 30 to the 87b terminal for constant power to the pump -- unswitched, so be sure to undo that swap once you reach your destination!

[geezer101]

I am a complete beginner at this and can barely do the oil switch method. I might try geezers method, but I already started on the oil pressure switch method and want to finish it. Maybe in the future I'll give geezers relay method a try, but I'm already close to finishing. Anyways what's the advantage of using the ready made kit over using the chintzy oil pressure switch?

Now as for the last wire mentioned, I can't for the life of me figure out where the fuel cut off solenoid wire is to hook up! May anyone with a 2nd generation MM help me get this damn thing wired up already. Just out of curiosity, does the oil pressure sensor switch use "Accessory" power, or "On" power? Also, does the weber choke use "Accessory" power, or "On" power? Sorry guys for being such a freaking idiot, but I really do like doing this and wish to learn.

Sorry, a bit of a misunderstanding there . I was referring to the on/off switch in that relay kit link I posted up. Do not discount yourself on effort. Auto electrics are tricky to master. Once you have hooked up a relay or 2 into a system, you get to understand how they work.

I have to point this out though. The carb is going to be full of fuel and killing the fuel pump will not be enough to shut the engine off in a worse case scenario like a roll over. You'd need to be able to shut down the ignition as well as the fuel pump. The oil pressure switch would need to be introduced into the engine system before power to the coil and fuel pump to ensure a full engine shut down.

[SubGothius]

killing the fuel pump will not be enough to shut the engine off in a worse case scenario like a roll over.

The safety switch simply prevents hosing down the scene of a crash with raw fuel in case the crash severs a fuel line. Killing the engine is besides the point, and it hardly matters for safety if the engine somehow keeps running after a rollover. Not sure a carb full of fuel can even function upside-down, for that matter.

[BJH324JH]

For power to the I terminal, you can see if any of those loose connectors have ~12V power when the key is on and not when it's off. If your Mikuni setup is like my '87, the fuel cutoff solenoid terminals are bundled into that multi-terminal connector block. You may wish to just cannibalize the old carb side of that connector, cut the wire pair at the cutoff solenoid, and splice onto that; one of those wires should get 12V switched current, and the other is a ground. You can tell which gizmo is the solenoid when you plug it in and turn the key, you should hear it click.

A relay is a switch in one circuit that's operated by electricity in another circuit. You want a NO SPST type (normally-open single-pole single-throw), which has 4 or 5 terminals: two operate the internal switch, which dis/connects power across the other two, or some NO SPST relays have an extra switched output terminal (called a "dual make" relay). When power flows across the control terminals, that energizes an internal electromagnet that closes a switch across the switched terminals.

Why use a relay? The electromagnet draws tiny current, whereas the switch can handle high current, so you can switch a high-current circuit with another one that's low-current, dodgy/unknown, or otherwise worth protecting. The circuit across the ignition key switch to the I and then P terminals may not be strong enough to drive the pump, or you may just want to protect your ignition switch and pressure safety switch by reducing the current demand across them, so we use that circuit to operate the relay, which in turn switches current directly from the battery (+) terminal to the pump.

This page explains and illustrates more about relays:
https://www.the12volt.com/relays/spdt-and-spst-automotive-relays.asp

Here's the basic wiring you'll use:
https://www.the12volt.com/relays/relaydiagram47.html

...where terminal 86 will take the 12V wire from your old cutoff solenoid , 85 will take the old solenoid (or any) ground, 30 will take a fused line from the battery (+) terminal, and 87 will go to the pump. If you get a dual-make relay with an 87b terminal, that allows for another trick you can do in a pinch: swap the wire from the 30 to the 87b terminal for constant power to the pump -- unswitched, so be sure to undo that swap once you reach your destination!

I think I may have figured it out where the fuel cut solenoid wire is. After looking at the manual for a bit and looking up what each solenoid does, I came to figure out that "Slow cut solenoid valve" is the "fuel cut solenoid valve". Just different names. Here is a picture of the fuel cut solenoid valve on the mikuni carburetor:

23471

It has red and blue wires going into a connection block, just like SubGothius mentione:

"If your Mikuni setup is like my '87, the fuel cutoff solenoid terminals are bundled into that multi-terminal connector block."

Now, there is two wires coming out the fuel cut solenoid. One is blue and the other is red. I believe one is ground and the other is power? Do I use both wires of the cut off solenoid , or just one?

[BJH324JH]

Sorry, a bit of a misunderstanding there . I was referring to the on/off switch in that relay kit link I posted up. Do not discount yourself on effort. Auto electrics are tricky to master. Once you have hooked up a relay or 2 into a system, you get to understand how they work.

I have to point this out though. The carb is going to be full of fuel and killing the fuel pump will not be enough to shut the engine off in a worse case scenario like a roll over. You'd need to be able to shut down the ignition as well as the fuel pump. The oil pressure switch would need to be introduced into the engine system before power to the coil and fuel pump to ensure a full engine shut down.

Ah okay, I understand.

[BJH324JH]

Just for confirmation, the fuel return line gets blocked off?

[geezer101]

...Now, there is two wires coming out the fuel cut solenoid. One is blue and the other is red. I believe one is ground and the other is power? Do I use both wires of the cut off solenoid , or just one?

You'd only need the power wire but now you are going down the oil pressure switch path you probably won't need to isolate the power in that connection. What would happen is the power that normally would go to that solenoid would be used to trigger the relay in an ignition on/off circuit.

[BJH324JH]

You'd only need the power wire but now you are going down the oil pressure switch path you probably won't need to isolate the power in that connection. What would happen is the power that normally would go to that solenoid would be used to trigger the relay in an ignition on/off circuit.

I took out the multimeter and tested the connection where the fuel cut solenoid hooked up to and it seems to have only about 10volts. Do I need to find another keyed ignition source? Here is a picture I took of the multimeter reading:
23472

[SubGothius]

That ~11V reading should be sufficient to trigger the relay. A fully charged battery should push about 14V, so that reading may indicate your battery is nearly depleted and/or needs replacement. To confirm, see if you also get ~11V across the battery terminals directly.

BTW, I notice you also already have the new carb's electric choke wired up, so if that's already hooked to an ignition-switched +12V source, you could just extend that from the choke to I terminal, instead of using the cutoff solenoid circuit at all.

Hm, now that I think of it, prolly best to have that choke lead go to the safety switch I terminal first, then wire the P terminal to the relay trigger terminal 86, then have the relay switched output terminals 87 and 87b go to the pump and choke respectively. That way, the choke is only powered when the engine is actually running, so you won't open the choke when you've got the key on but engine off, listening to the radio or whatever.


Just for confirmation, the fuel return line gets blocked off?

Yes, so I gather from other threads here. However, if you ever get vapor lock in the summer, you might consider using that to keep fuel constantly circulating through the engine bay and back to the tank, so it never sits still enough to vaporize anywhere.

[BJH324JH]

That ~11V reading should be sufficient to trigger the relay. A fully charged battery should push about 14V, so that reading may indicate your battery is nearly depleted and/or needs replacement. To confirm, see if you also get ~11V across the battery terminals directly.

BTW, I notice you also already wired a lead to the new carb's electric choke, so you could just extend that from the choke to I terminal, instead of using the cutoff solenoid circuit.

Hm, now that I think of it, prolly best to have that choke lead go to the safety switch I terminal first, then wire the P terminal to the relay trigger terminal 86, then have the relay switched output terminals 87 and 87b go to the pump and choke respectively. That way, the choke is only powered when the engine is actually running, so you won't open the choke when you've got the key on but engine off, listening to the radio or whatever.



Yes, so I gather from other threads here. However, if you ever get vapor lock in the summer, you might consider using that to keep fuel constantly circulating through the engine bay and back to the tank, so it never sits still enough to vaporize anywhere.

I just connected one end to the choke, the other end is hanging around not connected to anything. I tested the voltage on the battery directly and it gets 12volts. I did have to recondition it with a battery charger though. The battery might need replacing. As for the relay, is there one you recommend, or is the one geezer linked the one to use?

[85Ram50]

Just for confirmation, the fuel return line gets blocked off?

I blocked mine off in the engine bay where it connected to the hard line. If it were empty when I did this I would block it off at the tank.
SubGothius seems to know a lot more than I do about wiring. I figured the electric fuel pump wiring out for the first time from the leads Geezer and Pennyman gave me and a search on YT. Some of the info already on this site also helped, some was way over my head. So that post where I describe what I did it is the first time I ever did that.

[SubGothius]

D'oh! I just realized the safety switch already effectively IS a relay, just controlled by oil pressure rather than another circuit. So you can just run a wire from the battery (+) terminal directly to the switch I terminal, and wire the switch P terminal to the choke and pump. You don't even need switched ignition power, because the safety switch would only send power to the pump and choke when starting or when the engine is already running, and cuts power when the engine stops running.

[BJH324JH]

D'oh! I just realized the safety switch already effectively IS a relay, just controlled by oil pressure rather than another circuit. So you can just run a wire from the battery (+) terminal directly to the switch I terminal, and wire the switch P terminal to the choke and pump. You don't even need switched ignition power, because the safety switch would only send power to the pump and choke when starting or when the engine is already running, and cuts power when the engine stops running.

You are awesome, thank you so much for your help. This sounds like something my peanut brain can handle doing. I hope everything goes okay. My friend will have the fire extinguisher ready, just in case.

[geezer101]

The internet can be your friend - use it well. There will be plenty of schematics and videos to use as a guide (you will know what is good or bad as soon as the instructions include a fuse and relay and advise using an ignition on only power source) If some turkey is running accessories straight off the coil or the battery, you have found a "how not to" video...

[SubGothius]

I worked up some relay diagrams. Here's how it would work with the safety switch you've already got:

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23505&stc=1

However, when I tackle this same project myself soon, I plan to use a different safety switch that incorporates a terminal for the low-pressure light (instead of a (S)tarter terminal), so I won't need a T-adapter for the stock oil light switch; this setup would use a different type of relay wired like so:

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23506&stc=1

Edited to add:

I have found a 10 amp fuse is perfectly adequate for this. Also, I'd always put the fuse between the battery (+) and relay (not after the relay as in the second diagram above). The "N/C to starter" terminals would of course lead to the same terminal on the starter as the starter-trigger wire (the smaller wire connected to the starter).

I've also found cheap relays can fail quickly or sometimes overheat, which can cut power to the pump by surprise at inconvenient times, so I'm upgrading to this top-quality TE Connectivity 7-1393304-1 SPST relay (https://www.mouser.com/ProductDetail/TE-Connectivity-AMP/7-1393304-1?qs=%252BJ%252BJwDEtia0%252B3FfBV5uBhw%3D%3D). The SPDT equivalent would be their 6-1393302-0 (https://www.mouser.com/ProductDetail/TE-Connectivity-PB/6-1393302-0?qs=%2Fha2pyFaduiCoiaEfYEofVYqXW3Qmr8XMvPmYs4Cnzu pQLEp7JyKpQ%3D%3D).

[BJH324JH]

I worked up some relay diagrams. Here's how it would work with the safety switch you've already got:

23505

However, when I tackle this same project myself soon, I plan to use a different safety switch that incorporates a terminal for the low-pressure light (instead of a (S)tarter terminal), so I won't need a T-adapter for the stock oil light switch; this setup would use a different type of relay wired like so:

23506

You are pretty good at this electrical stuff. This stuff boggles my mind. I was wondering if there was a way to eliminate the t fitting because it looks ugly. Glad there is a way. Thank you for the help, I'm just waiting for my power brake booster hose, so that I can start her up. I'll keep you guys updated.

[SubGothius]

Here's an eBay search you can use to find a suitable oil pressure switch with warning light terminal:
oil (switch,pressure,sender) (86281,331347,14057554,4186352,swg1708,"swg 1708") (https://www.ebay.com/sch/i.html?_from=R40&_nkw=oil+%28switch%2Cpressure%2Csender%29+%2886281 %2C331347%2C14057554%2C4186352%2Cswg1708%2C%22swg+ 1708%22%29&_sacat=0&LH_TitleDesc=1&_sop=15)

Apparently the block threading is a 1/8"-28 BSPT (British Standard Pipe Tapered, aka ISO 7-1), rather than the more typical 1/8"-27 NPT taper, so you'll need an 1/8-27 NPT Female to 1/8-28 BSPT Male adapter like this:
https://www.ebay.com/itm/113237920183

BTW, I've noticed Standard and Wells seem to use similar part numbers starting with PS (for Pressure Switch presumably), but they don't match, so you can't assume, say, a PS122 is the same part from one mfr. to another. The OEM part nos. referenced in the eBay search above should be more reliable as a cross-reference.

[BJH324JH]

I cranked her up and nothing. I couldn't get the truck to start. In fact the pump wasn't running at all. I checked the electrical pump by hooking it up directly to the battery and I was able to get it running. Could my engine not be producing enough oil pressure and thus not causing the fuel pump to get electrical power? Truck ran fine before with old carburetor. Didn't show the oil pressure switch light on the dash with the old carburetor

[BJH324JH]

I checked the t fitting and it's as dry as can be. There is no oil going to the oil pressure sensor. Does that mean the oil pump is screwed up?

[SubGothius]

Hm, if it's been sitting a long time, the oil galleries may have drained fully and could take some time to fill up again. Try pulling the main coil wire to the distributor (so it won't fire up) and crank it over for a few bursts of about 5-10 sec. at a time each. Then see if you've got any oil in the Tee.

If that tee has any fork pointing upward, above where it screws into the block, that could be trapping an air pocket there. That's why it's best to have a Tee oriented with two forks horizontal and the other pointing down, or at least all forks level and horizontal, rather than having any fork pointing upward.

[BJH324JH]

Hm, if it's been sitting a long time, the oil galleries may have drained fully and could take some time to fill up again. Try pulling the main coil wire to the distributor (so it won't fire up) and crank it over for a few bursts of about 5-10 sec. at a time each. Then see if you've got any oil in the Tee.

If that tee has any fork pointing upward, above where it screws into the block, that could be trapping an air pocket there. That's why it's best to have a Tee oriented with two forks horizontal and the other pointing down, or at least all forks level and horizontal, rather than having any fork pointing upward.

Yes, that makes sense, I'll try that. It's been sitting for months.

[BJH324JH]

Cranked the truck multiple times, no luck. I hope it's the oil pump that needs replacing.

Great news, the truck started! To get the oil circulating everywhere in the engine again I had to remove the t fitting and plug the thread with an oil pressure switch while I pressurized the other pressure switch (The one with all the electrical connections attached to it.) with my vaccum/pressure gun.The vaccum/pressure gun basically acted as a "pressurized engine" and thus able to flip the switch inside which in turn, turned on the electric fuel pump and I was then able to start the truck and get the oil pump working. Doing this proved to be much more effective than cranking the engine for 10 seconds. That was taking too long or not working at all. I afterwards removed the oil pressure switch and it had oil in it. I then switched to the oil switch with the electrical connections on it to see if the engine itself could pressurize the switch and it got pressurized immediately and the truck started just fine. I now just have to put the t fitting back on and thread both the oil pressure sensors on it again now that the truck has oil in its gallies again. The truck runs rough, but I'm guessing that's because of the timing being off. It also doesn't stop immediately when the ignition is set to off. I think this is called dieasealing. Is this normal and safe? I want to thank Geezer101, 85ram50, SubGothius and everyone who helped get me to this point. Thank you very much!

[BJH324JH]

Okay, so I have yet to time the engine, I just couldn't wait to try out the truck. Could the transmission be out because I can barely reach above 55 going uphill on freeway. Honestly I thought this carb would fix that. That's one of the main reasons I got the carburetor.

[geezer101]

The dieselling and lack of top end power are related. Drop your idle speed by adjusting the throttle stop on the carb, then experiment with the ignition timing. The factory recommended timing settings no longer apply with the Weber and this part will be trial and error.

By the way - nice work with getting the oil pressure safety cut off working correctly :thumbup:

[BJH324JH]

The dieselling and lack of top end power are related. Drop your idle speed by adjusting the throttle stop on the carb, then experiment with the ignition timing. The factory recommended timing settings no longer apply with the Weber and this part will be trial and error.

By the way - nice work with getting the oil pressure safety cut off working correctly :thumbup:

Thank you geezer, I couldnt have done it without you guys. Seeing as the factor timing doesn't apply, do I just go by feel?

[geezer101]

I would try this - drop the idle, try to hold the engine rpm @ about 2000 and gently swing the distributor between advance and retard until the engine rpms jump by themselves, back it off a touch and try road testing it. Fingers crossed you'll see improvements in top speed and mid range (should shift nicer) and the dielselling should be tamed.

[BJH324JH]

I would try this - drop the idle, try to hold the engine rpm @ about 2000 and gently swing the distributor between advance and retard until the engine rpms jump by themselves, back it off a touch and try road testing it. Fingers crossed you'll see improvements in top speed and mid range (should shift nicer) and the dielselling should be tamed.

Thank you geezer, always appreciate your help. I don't know whether I should tackle this or let the carb shop do this. I don't know what tools to use. I think a tachometer might be needed.

[geezer101]

A cheap hand held dwell/tach meter will do the job. The dwell isn't much help on an ECM distributor system other than to tell you it's out of spec.

Here's my beef - new school shops can't (or don't understand how to) tune old school engines. There is a subtle art to digging up hidden performance in an old school and every shop I dealt with used the 'factory spec' tune. That's when I started doing my own tune ups and learning how to find that little extra. I had one bunch or muppets undo a good tune I performed on a friends Mazda 808 (40 minutes of dialling in the ignition and resetting the breaker points for optimisation) - when he picked it up from getting something else done to it, it was a slug compared to how it went in.

[85Ram50]

A cheap hand held dwell/tach meter will do the job. The dwell isn't much help on an ECM distributor system other than to tell you it's out of spec.

Here's my beef - new school shops can't (or don't understand how to) tune old school engines. There is a subtle art to digging up hidden performance in an old school and every shop I dealt with used the 'factory spec' tune. That's when I started doing my own tune ups and learning how to find that little extra. I had one bunch or muppets undo a good tune I performed on a friends Mazda 808 (40 minutes of dialling in the ignition and resetting the breaker points for optimisation) - when he picked it up from getting something else done to it, it was a slug compared to how it went in.

I usually walk away if they say "we make it like the factory built it" or some version of that. It is a red light warning that they do not know about your rig and may not know about motors in general. Almost every vehicle gets improved and fixed after it has gone into production. Design flaws and other items not built properly show up and need changes. Frequently owners improve them too. If your shop doesn't know this or know to look up Technical Service Bulletins for what has changed on your vehicle they are probably not reliable.

[SubGothius]

I usually walk away if they say "we make it like the factory built it" or some version of that.

Which could also just be tail-covering; they're less liable if they tune everything "by the book". The factory tune may have been nerfed for emissions rather than performance, and doesn't account for upgrades like a better carb, replacing points with electronic ignition, etc.

[BJH324JH]

Should I block this hose? I put my finger on it and its creating vaccum. I intend to put the original air cleaner on when I have the time.
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=23535&stc=1

The hose on the valve cover is the one I mean.

[geezer101]

You have 2 options - there is either an elbow under the base of the air filter mount you can install that connects to the breather hose (most likely will make it compliant for emissions) or put a smaller breather element on it. But don't plug it up or delete it as it helps crankcase ventilation and recirculates gas build up back into the engine to be burnt.

[geezer101]

Which could also just be tail-covering; they're less liable if they tune everything "by the book". The factory tune may have been nerfed for emissions rather than performance, and doesn't account for upgrades like a better carb, replacing points with electronic ignition, etc.

Book goes bye bye with a carb swap. The factory tune is a compromise between emissions and worst case scenario cold engine starts. If the tune is in the ball park it 'should' start. I'd encourage anyone who wants to learn sumpin' to buy feeler gauges, a hand held tach/dwell meter and a timing light (you're only going to need the timing light as a diagnostic tool to know what the base timing looks like. There's free performance up for grabs with some patience and trial and error.

[BJH324JH]

You have 2 options - there is either an elbow under the base of the air filter mount you can install that connects to the breather hose (most likely will make it compliant for emissions) or put a smaller breather element on it. But don't plug it up or delete it as it helps crankcase ventilation and recirculates gas build up back into the engine to be burnt.

Got it. Thank you very much.

[SaxMachine]

You can either remove the EGR valve solenoid and fit a blanking plate over it (easy to make) or just leave it in place with the vac hoses disconnected. The Christmas tree vacuum barb on the manifold needs to be removed and a threaded bung screwed into there. The water barb connection for the heater return and carb choke should be removed and a single upright barb installed (the original barb will most likely be paper thin from rust anyway) The rest of the vacuum connections are only vac thermo switches and pose no risk to vacuum leaks but you could delete them for appearances sake.

I went a little nuts with mine and completely cut off the EGR gallery running around the manifold plenum and sculpted the manifold. Mine was easier to do as it was off a Gen1 G63B and didn't have a lot of emissions control ancillaries on it and didn't have jet valves either (I had to prepare the manifold for repairs anyway as the water jacket cover plate under the plenum had corroded out and had a few pin holes in it). I capped off the gas gallery that runs through the head into that EGR gallery and ran a metric thread tap through the coolant port that is located on the carb mounting face/seat and installed a grub screw in there to seal it off. Not entirely necessary but reduces the risk of coolant somehow backing up into the plenum if the carb install kit manages to develop a leak.

Do you know what size threads the water barb has? I am doing this in my driveway and would like to purchase the single barb before I remove the one with the "T." Also, is that something I can just purchase at an auto parts store? Thank you

[geezer101]

I can't recall what the thread type was, but I did use an off the shelf manifold barb for a Ford to replace the 'T' barb that was on my manifold.

[SubGothius]

FWIW I couldn't get that stock T-barb to budge at all, had some hardened goopy white residue around the base indicating a PO must have applied some sort of thread sealant. I wound up just capping the small barb with a short length of fuel hose plugged with a short bolt and hose-clamped at both ends, bit of a kludge but seemed more reliable than using a vacuum cap to contain pressurized coolant long-term.

[robertson5347]

Does any of the generic or fake 32/36 dgev carbs. work?

[geezer101]

Does any of the generic or fake 32/36 dgev carbs. work?

It would be near impossible to know which of the 'licensed copies' are any good. The primary fault with them is the internal metering galleries and the way they are machined/manufactured. Genuine Webers have emulsion jets that can be swapped out for tuning. A member recently used an 'EMPI' 38 DGES copy that is working well.

[SubGothius]

Indeed, Webers are designed to manage fuel and air metering with precision-engineered air and fuel passages, so they depend on every passage being finished to exacting tolerances. The clones don't seem to have that finishing step done, or at least not done well and to spec, so it's luck of the draw if any given unit just happens to have them all close enough to work in harmony as designed.

I do wonder if the bright-dip the clones are evidently subjected to (which genuine Webers aren't) could be part of the problem; I'm not entirely clear how that process works, but if it adds or removes any material, that could be throwing tolerances out of range.

I also wonder if EMPI does anything with their clones that may improve matters over units that come direct from the factory.

[geezer101]

They've been making them for long enough to be able to get it right by now. It wouldn't be worth trying to mill the knock off copies to make them operate correctly compared to simply buying a properly designed and manufactured carb like the OG Weber. There must be some info on the crap carbs that goes into depth on why they are so bad :rolleyes:

[Chairwolf]

New guy here, subscribed!

[Chairwolf]

Just checking to see if this thread is still alive. I have a 1988 Mighty Max with a 2.0 liter engine. I'm the ORIGINAL OWNER believe it or not!
I've just read the entire thread. I have a Weber 32/36 DGEV carb on my truck. I'm having the "no-power" problem. It will idle like a champ, but it struggles to go over 25 mph, and barely goes up hills. I'm looking at the vacuum/spark advance issue, and possibly the throttle cable. When the carb was put on, I remember the cable being a little too short due to the adapter plate adding about 3/8" to the height of the carb. Has anyone run into an issue with this? I made a little connector out of a piece of aluminum to make a connection. I can post pics later.

Back on the vacuum issue, base on previous comments, did anyone settle which ports to connect to which between the carb and distributor vacuum?

Thanks!

[geezer101]

I found a set up guide for base tuning the 32/36 on another forum (hey, this may already have been covered and posted but it's fun trying to find specific info through all of the threads...)

https://www.yotatech.com/forums/f120/proper-only-right-way-tune-weber-32-36-a-240521/ Step by step guide for mixture and idle adjustment.

When you installed the carb, did you do it with the fuel bowl facing the front of the engine bay or the rear? Facing the rear will cause the fuel float to shut off the needle and starve the engine out. Any other info like has it only just started doing this or has it been like it since installation?

[SubGothius]

When you installed the carb, did you do it with the fuel bowl facing the front of the engine bay or the rear? Facing the rear will cause the fuel float to shut off the needle and starve the engine out.

Just to expand/clarify that point, float bowl in the rear will make it run lean/starve on takeoff/uphill, and rich/flood on braking/downhill, which are the opposite of what's ideal. While you can turn around a Weber DGEV to put the float bowl in front, that makes it so the linkage cable has to come at the carb from the battery side, whereas the mirror-image DFEV model can keep the cable on the exhaust side with the bowl in front.

That said, I'm running a DGEV with the bowl in the rear, and it's not been any major problem as long as I brake gently well in advance, only wants to stall out when I need to brake abruptly.

[Chairwolf]

It's facing the front. Throttle cable is toward the firewall.

[Chairwolf]

I found a set up guide for base tuning the 32/36 on another forum (hey, this may already have been covered and posted but it's fun trying to find specific info through all of the threads...)

https://www.yotatech.com/forums/f120/proper-only-right-way-tune-weber-32-36-a-240521/ Step by step guide for mixture and idle adjustment.

When you installed the carb, did you do it with the fuel bowl facing the front of the engine bay or the rear? Facing the rear will cause the fuel float to shut off the needle and starve the engine out. Any other info like has it only just started doing this or has it been like it since installation?


Thanks for the reply! Let me add that this truck has been sitting for a number of years and not driven. It starts and runs. It will idle and rev like a champ!! It sounds like it wants to win the Indy 500. I mean, it idles a little high, but smooth. I've got the Weber instructions, and have set the mixture and high speed idle so it will start pretty well and idle, and under load (sitting with foot on brake and putting it in gear), it idles ok. It just goes "blah" going up hills.

[geezer101]

This may be a jetting issue. Getting idle and primary jet sizes right can make the difference from it being a slug to running like a freight train.

[Chairwolf]

I'm no expert in the Weber department, but the carb has whatever size came with it from the factory. Is there a "default" size that they normally send, or is it customer specified? I had this carb ordered and installed by a mechanic, so unfortunately I don't know what is in it.

It will drive pretty well in 1st and 2nd gear, but after that, it detonates like crazy, even on flat ground. It's an automatic, BTW. I've ordered a new distributor vacuum advance, which should be here in a few days. If that makes no difference, then at least I know the spark advance is not the problem. We'll see! :) Any other thoughts? And thanks.

[SubGothius]

It will drive pretty well in 1st and 2nd gear, but after that, it detonates like crazy, even on flat ground. It's an automatic, BTW. I've ordered a new distributor vacuum advance, which should be here in a few days. If that makes no difference, then at least I know the spark advance is not the problem.

Unless the static/base advance is the problem? That could explain the detonation if it's too far advanced.

[geezer101]

There's the missing part of the puzzle. Need to experiment with the tuning. Webers are vacuum sensitive - regap your plugs to 0.85-0.9mm and adjust the distributor timing until the detonation backs off. Also try to avoid using regular gas and go up to the next octane (91+) It'll run better on it.

[Chairwolf]

Unless the static/base advance is the problem? That could explain the detonation if it's too far advanced.

By "static/base" do you mean loosen the distributor and rotate it slightly clockwise a bit? I don't have a timing light, so I'd have to just tweak it and see what happens.

[Chairwolf]

There's the missing part of the puzzle. Need to experiment with the tuning. Webers are vacuum sensitive - regap your plugs to 0.85-0.9mm and adjust the distributor timing until the detonation backs off. Also try to avoid using regular gas and go up to the next octane (91+) It'll run better on it.

Can do on the gap and timing. I'll try that and the gas! Thanks

[SubGothius]

By "static/base" do you mean loosen the distributor and rotate it slightly clockwise a bit? I don't have a timing light, so I'd have to just tweak it and see what happens.

Yeah, that's it -- how much advance is dialed-in for the dizzy itself at idle, before centrifugal/mechanical advance and vacuum advance kick in. BTW, your local AutoZone / Advance / O'Reilly's may have timing lights available for loan/rental.

[geezer101]

Try dynamic tuning as well. You'll need a dwell/tach meter to observe engine RPM's. This is a relatively straight forward procedure. Reset the plug gaps as I've recommended earlier and have 91+ in the tank (you'll be tuning the engine to run on a higher octane fuel and may need to re-tune if you go back down to regular pump gas) Start the truck, loosen off the distributor retaining nut so you can adjust advance/retard. Hold engine RPM @ 2000 and gently adjust the engine rpm between advance and retard until you hit a sweet spot and engine RPM's jump by themselves, then lock the distributor retaining nut. Take it for a drive and see what it's doing as you may need to make further adjustments.

*timing light is not much more than a diagnostic tool to see if you've getting misfire or some event is causing timing fluctuations. If you've set the carb throttle stop and have cold and hot idle RPM's right, you can tune the engine by feel.

[Chairwolf]

SubGothius and Geezer101,

Yesterday I removed the distributor cap and checked the vacuum advance by sucking in on the vac. tube. The advance would move, but would not hold its position, so I believe the valve is leaky. I have a new one ready to install. It might be a few days before I get that done and have a chance to check the results. Will also re-gap the plugs.

This truck needs other things done to it! I took it for a ride yesterday, and noticed that the steering wheel rotates left and right a little at speeds above 40mph. So it needs some front end work! This will be a lengthy project vehicle! But thanks for your advice, I will work on these suggestions and report back as soon as I can!!!

[Chairwolf]

Yeah, that's it -- how much advance is dialed-in for the dizzy itself at idle, before centrifugal/mechanical advance and vacuum advance kick in. BTW, your local AutoZone / Advance / O'Reilly's may have timing lights available for loan/rental.

I'll probably do that, or maybe check Harbor Freight. I don't mind buying a tool, but would rather not buy something that I'll probably not use much if at all! :)

[geezer101]

When you've installed the new vac advance, give the mounting platter a good blast with WD40. They gum up and it causes 'lag' - won't respond on quick open throttle and doesn't release fast enough off throttle.

[Chairwolf]

Ok, the vacuum advance I received was for a 2.6, not a 2.0. So I returned it, and ordered a full distributor with the advance on it. Should be here by the weekend. No other updates so far!

[Chairwolf]

Ok, the new distributor is installed and the truck runs. Still has difficulty starting, but I found a video channel by a guy in South Africa who knows Webers very well. He lists 5 things to check. I think my problem could be either distributor advance, or vacuum leak. Here is the video and his channel, which seems to be excellent: https://www.youtube.com/watch?v=t-VCi1lS8vU

Any thoughts?

[Chairwolf]

I think my next check will be running the engine and using carb cleaner to try to find vacuum leaks.

[Chairwolf]

Well, fooey! After I put in the new distributor, it ran fine. I re-gapped the plugs to .80 (highest gap I have on my gapper) and it wouldn't start, so I went back to .44 and it ran. Next time I tried (few days later), it wouldn't start. I haven't been able to start it since. I put in a new rotor, adjusted the distributor, cleaned the plugs with a wire wheel. Still won't start. I'm thinking air, fuel, spark. I have air, it's getting fuel, it has spark. Timing *seems* to be right. I tried my old trick, taking a plug out, plugging it to the wire, and setting it close to the cylinder hole, but not inside. Then crank. When it is time for the spark and power stroke, it ignites the air/fuel mixture and pops, so I know I've got air, fuel, and spark. (Also cures flooded cylinders!) So, now I'm thinking carb. The truck has been sitting for about 5-6 years. Maybe I need to rebuild the carb. Any ideas?

[geezer101]

Reduce your plug gap and adjust your advance timing. You will need to aim for 0.85mm/0.9mm to get a good, aggressive arc (.033/.035 in) The Weber requires more aggressive timing and is sensitive to engine vacuum.

[Chairwolf]

Ok, update time! I gapped the plugs as recommended to between .033 and .035. Adjusted the timing, also added a missing ground strap. Still refuses to start. I ordered a weber rebuild kit and a jet kit. I'm thinking that maybe the 5-6 years of not running has allowed the ethanol gas to gum up the works. I'm also thinking I should confirm that the coil is working. I will also confirm good spark. I've replaced the distributor and rotor, and also CLEANED the plugs. I may put in new plugs and wires, and if needed, coil. That should cover the spark question! So next, confirm good carb, then I may drain the gas (If I can figure out how; siphon hose wouldn't reach the gas. Any tips?).

I'm open to suggestions! Thanks

[geezer101]

I think you need to drop the tank out and flush it. Siphoning will only get so much and I've had experience with a tank that was full of silt. First time I got the car on the road it pulled a ton of junk up into the lines and killed it.
It will also give you a chance to inspect the overall condition of the tank and maybe encourage you to give it a coat of paint for future protection - and it looks pretty :)

[Chairwolf]

I may do that, but later on. My to-do list is already getting pretty long! :) I'm hoping to get it running and burn most of the old gas up.

[Chairwolf]

Ok, another update. I got her running! Here's what I did:

- I connected a manual fuel pump to the fuel line in the engine compartment and pumped the old gas out, and replaced it with fresh gas.
- Rebuilt the old Weber with the official kit.
- Set the crank to TDC and got the distributor timing right.

and now she runs! It idles fast, and I'm having a little trouble with my throttle cable linkage coming loose. I have the automatic trans, so I need the kick-down linkage. I may end up putting the original throttle connector back on, but as I recall, that got in the way of the choke linkage. We'll see.

So, current issues:
- throttle cable coming loose
- idles great, but dies under load.

Any suggestions or threads you can point me to where these things have already been hashed out?

Thanks!

[geezer101]

It will need to idle fast if you have an auto trans - how fast is it? You are going to have to experiment with ignition timing to run the Weber. Did altering the plug gap make the difference?

[Chairwolf]

It will need to idle fast if you have an auto trans - how fast is it? You are going to have to experiment with ignition timing to run the Weber. Did altering the plug gap make the difference?

At present, the gap is .033. I noticed when I did the rebuild that the "full power valve diaphragm" had a little pucker in the rubber. After doing the rebuild, and some more googling, I learned what that thing did, which is to enrichen the mixture at full power. So maybe that's the problem. I ordered a new one from PegasusAutoRacing.com. I'll put it in when it gets here and see if it helps.

When I attempted to drive it, it stalled as soon as I put it in gear. When it would try to go, it rattled. Do you think the valve will fix this, or maybe advance the timing a little more, or something else? I may also need to re-check the float settings. This is my first time messing with a carb to this level, so forgive my "newbie" questions! If it sounds like I'm not familiar with the weber, it's because I'm just learning. :)

[geezer101]

It sounds like timing...? If it's rattling straight on throttle it seems like it's over advanced. This is an awful way to adjust idle, but back off the advance to drop idle speed and see what it does. Normally to set idle you'd warm it up, set the throttle stop and then adjust timing. The thing with the Weber is the added vacuum it produces - it automatically tries to pull vacuum advance straight from the get go.

[SubGothius]

I just feed manifold vacuum to the advance, ever since I found out the only reason for ported vacuum (taken from the carb just above the closed throttle butterfly) is to reduce emissions at idle by raising combustion temps. Manifold vacuum applies full advance at idle, reducing combustion and engine temps.

[Chairwolf]

It sounds like timing...? If it's rattling straight on throttle it seems like it's over advanced. This is an awful way to adjust idle, but back off the advance to drop idle speed and see what it does. Normally to set idle you'd warm it up, set the throttle stop and then adjust timing. The thing with the Weber is the added vacuum it produces - it automatically tries to pull vacuum advance straight from the get go.

I'll give it a try! Thanks

[Chairwolf]

I just feed manifold vacuum to the advance, ever since I found out the only reason for ported vacuum (taken from the carb just above the closed throttle butterfly) is to reduce emissions at idle by raising combustion temps. Manifold vacuum applies full advance at idle, reducing combustion and engine temps.

Interesting... sounds like doing it this way would make it easier to tune as well, wouldn't it?

[SubGothius]

Interesting... sounds like doing it this way would make it easier to tune as well, wouldn't it?

Hm, not sure about that, but you would need to pinch/disconnect the vac advance hose in order to set your static base advance at idle properly.

[Chairwolf]

Just found this little gem for those looking for a kickdown linkage for auto trannies:

https://www.carburetion.com/Products/ProductDetails.aspx?Part=444.614.46


http://www.carburetion.com/Images/weber/CU4.614.46.jpg

[solartony]

the Mikuni 32-35DIDTA carb has 5 mounting bolts to attach to the manifold ...


4 hexagon head bolts are easy to locate around the double barrels opening, in a rectangle configuration, ...




where's the fifth bolt ?

[kentleybeats]

I believe that is for the Weber carbs, not the Mikuni. Also, thanks for the 7 pages of info, all. Need to track down a vacuum leak on my Weber 32/36.

[SubGothius]

Webers only have 4 bolts, also in a rectangle pattern but different from the Mikuni pattern, hence the need for adapters.

Looking at the base of my old Mikuni I only see the 4 bolt holes, so perhaps any 5th bolt may depend on the model year or engine spec. I notice some adapters have a spur off the main rectangle, so that's prolly where the 5th bolt would be if present for your year/engine.

[Chairwolf]

Re-activating my account