Weber 32/36

[FMS88]

So I tried the starter fluid and the timing. Still the same. I was doing some other testing and noticed the spark seems weak. Could that be a problem and if so, what could cause it? Also, I know the vacuum system is obsolete but from looking at wiring diagrams the gray control box on the drivers side has like 2 ignition wires that hook into it. Do I need to have that hooked up?

Weak spark could be due to poor ground or harness connections. Check the battery-to-frame-to-block and the head-to-firewall cables for continuity and clean their contact surfaces. Then check that the coil, resistor block and distributor wiring connections are clean and secure. The coil or ignition igniter in the distributor could be failing, but if it ran fine before the Weber install, I doubt these are causing the starting problem.
I‘m not sure about the ignition wires to the gray device box. My schematic shows only one, a black and white wire from the resistor block to a choke relay in the box. Like the vacuum lines with the Weber, the harness connections to the box no longer have a purpose. I don’t think it needs to be connected.

What is the power source for the Weber’s choke? Maybe it’s competing with and killing power to the starting ignition? Look at this thread which describes a loss of spark after a Weber install: http://www.mightyram50.net/vbulletin...spark-to-plugs . See if yours starts after disconnecting the choke wire like rranger found. If it starts, find another power source for the choke. It needs to be energized only when the key is in the "On" position.

[pacheco2189]

Still nothing, all grounds are good, all connections are clean and secure. My weber choke is connected to a wire that use to plug into the old carb. I attached pictures of the wiring. I hooked everything back up the same exact way it came of but something seems off.

wire1.jpgwire2.jpgwire3.jpg

[FMS88]

Hmmm. I'm running out of possibilities. Nothing in the pictures looked wrong. Just to be clear, when you tested for spark, was it at the plugs?

[maxdsm]

Put a accel or msd aftermarket coil pack on it . My g63b did the same with weak spark after I rebuilt it . Starts up everytime now .

[bigwavedave]

Hey guys,

So i decided to tackle the weber project yesterday. I got the genuine weber 32/36 DGEV installed and the truck is starting and running fine. I have the idle and mixture screws tuned according the installation instructions. Fast idle screw is set to 2,000 RPM, idle speed screw is 1 1/2 turns in, and mixture screw is 1 1/2 turns out. The installation of the carb was straight forward, but there are a few things that I'm unsure about though so maybe someone here can shed some light for me. Mostly what to do with all my old vacuum lines. I have 1989 G63B manual with A/C.

1. I'd like to keep the vacuum lines in the engine bay for the emissions look, does anything need to be capped off not and just tucked away?
2. #8 in the installation instructions say to "Disconnect the evaporative emissions lines from the carb and air filter at the charcoal canister". does this mean to completely remove or cap off the lines coming off the charcoal canister labeled "to carb" and "to A?C"?
3. #9 in the instructions says "disconnect EGR valve and thermal switch next to it, they will disconnected and not be used". I disconnected the large vacuum line on the bottom oft he EGR as well as the small line going into the top, but which switch needs to be unplugged? There are three all in the same area just to the left of the EGR going into the thermostat housing.
4. #11 in the instructions says "Remove the two exhaust tubes from the exhaust manifold and use 1 1/4 plugs supplied to plug the holes". There was only one hole tp be plugged coming out of the manifold. It was the one that had the large metal pipe coming out of it going to the air control valve. I did remove the metal tube coming off the manifold and the entire secondary air valve assembly and used the supplied plug to the the hole in the manifold.
5. #12 in the instructions says "plug all open vacuum lines and thermal switch fittings on the intake manifold. make ABSOLUTELY SURE there are no connections to the EGR, the only vacuum used if the the power brakes". I'm unsure of exactly what I need to plug off here. Both lines going to the EGR have been disconnected and the factory vacuum line going from the brake booster to the intake manifold was untouched and still in place.
6. How does my electric choke connection look? Acceptable? it is a keyed power source, but just want to make sure with you guys its OK and if there isnt a better place to hook it up.
7. The vacuum line going from the carb to the distributor. There are 2 vacuum lines on my distributor: one coming off the side and one coming out of the bottom, which is the correct one to use and does the other need to be plugged or left open?
8. Fuel return line. Right now I have the return line coming off the fuel pump connected via a wire barb to the line going back to the tank. Is this correct?
*I have a Carbole electric fuel pump P/N 42S that I plan on installing in the next few days that will eliminate the stock mechanical pump. Once i install this electric fuel pump what will I do with the return line?
9. The trhottle return spring. is there a right and wrong way to install this is or is it just a make it work as best as possible kind of thing?

Thank you for any and all input!

[camoit]

So far everything looks fine.

[SubGothius]

If you've got a box on the driver's side inner fender with a bunch of vac lines running to it, that's a control box for the stock Mikuni carb, so you may as well pull that along with all vac lines connected to it, which will simplify things enormously.

That should leave a "tree" of open vac hose barbs screwed into the manifold, so you just need to cap those off, or IMO better yet run a short length of vac hose between pairs of those barbs and then just cap any odd man out (as caps tend to deteriorate more readily than hose does). Some ppl even unscrew that tree and plug the hole, but it's a weird 1/8"-28 BSPT thread (not the US-typical NPT) that you'd prolly need to special-order a plug for off eBay.

You don't have to cap any barbs attached to sensors/senders, as those aren't open to manifold vacuum.

[geezer101]

Jeez, the vac lines give me anxiety just looking at them. The concept of diagnosing a vac leak though... definitely remove the feedback system for the Mikuni carb unless to need to BS your way through emissions inspections.

[SubGothius]

9. The trhottle return spring. is there a right and wrong way to install this is or is it just a make it work as best as possible kind of thing?

Here's how I did mine:

IMG_20200709_190524.jpg

[geezer101]

^looks like a perfect set up

[geezer101]

I thought I'd put up a link to a YT video of a guy doing the 32/36 swap on his 2.6. The only errors he has made is not installing an electric HVLP fuel pump and instead using a fuel pressure regulator on the factory fuel pump and simply repurposing the fuel cut power from the original carb to run the electric choke which would've saved time and effort -

https://www.youtube.com/watch?v=3JH8...2%80%99sGarage

*the important info is on blocking the coolant port

[88dodge]

I thought I'd put up a link to a YT video of a guy doing the 32/36 swap on his 2.6. The only errors he has made is not installing an electric HVLP fuel pump and instead using a fuel pressure regulator on the factory fuel pump and simply repurposing the fuel cut power from the original carb to run the electric choke which would've saved time and effort -

https://www.youtube.com/watch?v=3JH8...2%80%99sGarage

*the important info is on blocking the coolant port

Why cant you use the original fuel pump with a regulator?

[camoit]

Why cant you use the original fuel pump with a regulator?

it’s because 90% of the regulators on the market will slowly increase pressure above the 2 psi limit. And most of the people that say it is fine have never put a gauge on the carb side and run with it. If they did they would quickly see that the only way to actually limit the pressure is to use a regulator with a return line to the tank.

[88dodge]

it’s because 90% of the regulators on the market will slowly increase pressure above the 2 psi limit. And most of the people that say it is fine have never put a gauge on the carb side and run with it. If they did they would quickly see that the only way to actually limit the pressure is to use a regulator with a return line to the tank.

so the fuel pump you would run is 2psi, so would this pump be ideal?

https://www.holley.com/products/fuel...s/parts/12-426

[geezer101]

It will need a higher flow rate than that to supply a Weber. 3.5 psi is closer to the ideal fuel pressure as well. The Mr Gasket 42S pump meets these requirements but it's kinda pricey - the Carbole 42S pump is identical excluding the stickers on the pump body and is literally half the price. Some people recommend the Carter P4070 but my experience was less than favourable (really noisy, expensive and the pump failed causing metal chaff to be coughed up into the fuel line)

[SubGothius]

I like the Carter P90091 myself -- smaller, quieter, and a simpler gerotor design completely different from the rotary-vane P4070 and generally a bit cheaper, too. Native pressure is exactly right for a Weber with smooth flow (unlike the pulsing delivery of most cheap solenoid-driven piston-action pumps), never had one fail in the 15+ years I've been using them [knock wood].

[geezer101]

There you go 88dodge - you have options

*thanks SubG. And it looks like most vendors supply a metal fuel filter as part of the packages starting @ $70ish USD

[SubGothius]

And it looks like most vendors supply a metal fuel filter as part of the packages starting @ $70ish USD

Yes, as standard eqpt. Carter includes a pre-filter attached by semi-permanent crimp-on hose clamps, so I suspect it's only there to protect the pump from coarse chunks and likely just has a fine stainless-mesh screen inside, so I'd still add a post-pump filter with conventional cellulose media, prolly underhood near the carb where it's more accessible. I'm seeing the P90091 available from Amazon at $46.60 USD shipped.

[88dodge]

Yes, as standard eqpt. Carter includes a pre-filter attached by semi-permanent crimp-on hose clamps, so I suspect it's only there to protect the pump from coarse chunks and likely just has a fine stainless-mesh screen inside, so I'd still add a post-pump filter with conventional cellulose media, prolly underhood near the carb where it's more accessible. I'm seeing the P90091 available from Amazon at $46.60 USD shipped.

Thanks guys, I do appreciate all the help you guys give me

[camoit]

A stock pump puts out 7 to 10 psi depending on how old the springs are. The flow is fine from them. They just cause the carb to over fill all the time and it will run rich

[SubGothius]

A stock pump puts out 7 to 10 psi depending on how old the springs are. The flow is fine from them. They just cause the carb to over fill all the time and it will run rich

Flow is fine, but pressure is excessive for a Weber, forcing the needle valve off its seat when the float should be holding it closed, and putting a regulator on it to reduce the pressure stresses the pump mechanism/membrane, eventually killing the pump. Electric is just the better, simpler, more reliable way to go.

[RamRock50]

Hey everyone,

I'm trying to find posts/threads that show how to do the electrical for wiring up an electric fuel pump for a weber carb. I've tried looking in this thread, but I didn't find much. Is there a good reference for how to do that?

[85Ram50]

RamRock
Look in the wiki. I tried to find my own posts and pics of what I did, but they seem to be gone. I barely remember what it looks like.

[SubGothius]

Check my posts in this thread for relay wiring, where/how to mount the pump, etc:

http://www.mightyram50.net/vbulletin...r-carb-install

[88dodge]

Hey everyone,

I'm trying to find posts/threads that show how to do the electrical for wiring up an electric fuel pump for a weber carb. I've tried looking in this thread, but I didn't find much. Is there a good reference for how to do that?

My father and I wired it up to the wires for the emission box that we took out, it works great, we also used another wire that went to the emission
box for the electric choke as well