fuel pump questions, Weber conversion

[2nup350]

I'm installing my newly gotten 2.6 and it's got a Weber bolted to it, and no fuel pump. I need to figure out what to do.
I've got a two port 79-80 fuel pump on my old engine. would I need a regulator to run it?
I could go electric- do I need a regulator with that? a Facet pump should do and is cheap.
I could get a three port pump from an 81 up truck for about $20- this should have a built in regulator right? what's it set to?
If i do need a regulator- get a return style one? what model?
I'm sure these questions have been asked before but I've not found any clear answers.

[2nup350]

I'm installing my newly gotten 2.6 and it's got a Weber bolted to it, and no fuel pump. I need to figure out what to do.
I've got a two port 79-80 fuel pump on my old engine. would I need a regulator to run it?
I could go electric- do I need a regulator with that? a Facet pump should do and is cheap.
I could get a three port pump from an 81 up truck for about $20- this should have a built in regulator right? what's it set to?
If i do need a regulator- get a return style one? what model?
I'm sure these questions have been asked before but I've not found any clear answers.
UPDATE- thought of another option- the Jeep three port fuel filter has a metered orifice that should maintain 3psi and if installed between the 2 port pump I have and the carb allow me to hook up the return back to the tank much like original. right?

[geezer101]

You should use an electric fuel pump. Using a regulator on the factory mechanical pump will eventually kill the pump. My recommendation is to use a Carbole 42S electric fuel pump from ebay. They're cheap to buy and are identical to the Mr Gasket 42S fuel pump, only less than half the price (they are the same pump - the model number on the body is the give away) They are a high volume, low pressure pump which is what you need to run the Weber carb. Easy to rig up. You don't necessarily need to remove the mechanical pump but you can make your engine look less cluttered by taking it out and using a block off plate.

[2nup350]

how about the jeep filter option?

[geezer101]

Is it a filter or a fuel recirculation cannister? Funnily enough Mitsubishi used a similar thing to split fuel delivery between the main fuel inlet and the accelerator enrichment jet. They were both available in metal and plastic but they did away with them when they changed the design of the mechanical fuel pump to a dual outlet (the metal cans rusted and the plastic ones sometimes cracked or split).

[2nup350]

The jeep filter on the Mr Gasket 42s pump yielded 2 psi to the carb. I installed the pump at the tank and the filter in the stock area for the original vapor separator- I'll try that too just to see what happens. I've not run the truck yet but will report later. I may make up a restrictor for the return line to get the pressure up if I need it. without the filter, just on the pump I was reading 4.5 lbs. will report further progress next week.

[pennyman1]

with 4.5 at the pump, you won't need a regulator or restrictor - the pressure drop should put it in the 3 - 3.5 range for the Weber.

[2nup350]

I'm running the Jeep filter. 2psi. it works just fine. the original vapor separator also yielded 2psi. I was getting 4.5 at the carb without a regulator and the engine didn't run differently, so I figure I'm okay plus the pump will be cooler - I'll check the plugs in a week.

[hutch]

Question: Why can't you just run the stock mech. pump?

[2nup350]

Question: Why can't you just run the stock mech. pump?
Weber carbs do not like "pulses" in the fuel supply. And the stock pump puts out 6 psi- too much for a Weber.

[geezer101]

Weber carbs do not like "pulses" in the fuel supply. And the stock pump puts out 6 psi- too much for a Weber.

The Weber will flood from over pressurisation and it will be a pig to run. And then trying to rectify the fuel pressure issue by adding a regulator to the factory mechanical pump will eventually kill the pump. A HVLP (high volume, low pressure) electric fuel pump solves all issues involved with installing a Weber.

[Law Dog]

Been running a factory pump for a few years now with a pressure regulator have not had a problem yet!

[pennyman1]

some 2nd gen mechanical fuel pumps can work with a reg, but I have no idea how to tell which one it is. Something to do with the feedback circuit in the pump.

[Mighty87]

I am doing this on my mighty max am curious. About my return line. Do I just by pass the return on the fuel line? I am going to purchase the help fuel pump and wanted to know what I need to purchase

[yamahlr]

I have been running an AC Delco EP42S electric pump mounted by the tank with excellent result for over 20 years. About $45 or so online.

[pennyman1]

Same as the Carbole one even to the part number with 42S.

[85Ram50]

EDIT Install electric fuel pump 1st gen Mighty Max/D50 for greenhorns.

If you found this by search got to post #37 in this thread for my summary of what I did. END EDIT



But what about the return line? I am looking and $52.98 shipped from RA

Where do I splice into the power for this?

[geezer101]

The fuel cut solenoid wire going to the original Mikuni carb is the best place to take power from for the electric fuel pump (sort of thick black wire with a white stripe and a female bullet connector on the harness end of the loom). It is bridged into the ignition circuit and is only live with the ignition on. Cap the return line off - but don't plug the fuel vapour hose going to the fuel tank. It can cause grief by vapour locking the tank. Mystery engine cut outs, especially on hot days...

[85Ram50]

I see no such wire. could be it was cut out before I owned it. Where does it come from?

[85Ram50]

There is a heavy black wire that comes out of the harness on the front of the driver wheelwell with a red stripe that used to hang loose. Before I decided to take care of it myself I paid Dodge to try to fix the previous Weber carb. The mechanic connected that wire to something. I haven't crawled under but I think he ran it to the starter.
Could that be it?
I have the AC Delco fuel pump coming.I decided to remove the interior bed panels and properly remove those bolts for the skirts. I will use trim tape in that spot when I remove/reinstall the skirts. It will be easier on my body. I've got the bolts out, not yet tried to unstick it from the sealer.

[geezer101]

I don't recall seeing a black/red wire but there could always be the off chance that someone in their finite wisdom changed the colour coding. Easy way to figure it out - turn the ignition on and see if it's live. It shouldn't go to the starter as it will only be hot when it's cranking. I need to take a look at my donor harness to give you an idea of where the fuel cut wire is situated when compared to the coil wiring connections.

[85Ram50]

Thank You Geez

[85Ram50]

I have the skirt off, I am unsure of what the FSM is showing me. I can tell the fuel supply because I installed that filter. I am unsure of the return line. I am thinking it is the line coming from the left then up to that valve which is closer to us and to the right of the filter in the picture. If that is it do you guys plug it on top of the tank or ??

23025

[geezer101]

That little plastic canister next to the fuel filter is part of the tank breather system (don't mess with it - bad things will happen) There's 2 lines tapped out from the tank below the tank halves seam line. The one below the fuel pick up connection is the return line. Luckily I have a spare tank sitting out next to my truck that I could visually refer to lol.

[85Ram50]

I was going to put in a new filter of the same type since I already have it. is there some other one I should use?
Any luck on that wire Geezer? I went through the whole FSM siring section and fuel section and found nothing about a fuel solenoid.

[geezer101]

If you trace back the wiring harness from the starter motor (starter solenoid wire is black with a yellow stripe) and the temp sender wire (yellow with a red stripe) there will be a black with white stripe wire taped into that section of the harness (it should be about the middle before joining the main harness). If it's been cut off, you'll be able to find it by unwrapping the electrical tape and tapping into the existing wire. Sorry about not getting back sooner with the info.

[85Ram50]

Thank you Geezer101. I checked. It is that black wire with the red stripe. It has a male bullet connector on the end of it. I'm not sure if the mechanic changed that from female. The blue wire goes to the choke, the yellow with red stripe goes to the sensor and the middle black wire red stripe is the one that mechanic connected up to the starter (I felt it I did not see it) because if I remember correctly it was hot when it was on. I checked both the choke wire and the black/red stripe wire are hot(11.5dcv) with the key on and cold when the key is off.
So that is sussed. I guess I need to complete this work before trying to figure out why my instrument panel displays intermittently. That will be another post. Off to get the steel for the pump mount and do other errands. hopefully be back at this by later today.

[geezer101]

Good that you figured it out. Hmm, someone didn't know the rules about live circuits. All hot wires from the harness should always be female sockets - just in case it gets unplugged and comes in contact with the chassis or engine (or possibly another live circuit) It might be a PITA but you should consider crimping new ends onto it as a precaution (if you can get ones with silicone boots on them that would be the best thing to use).

[85Ram50]

I just read the instructions. It recommends a PS9or equivalent oil pressure switch be part pf the power circuit. Is that already part of the circuit or do I have to add this in? If I have to add it I will need instruction to make sure I wire it correctly. Here is a pic of the instructions, it is one page. I expected more specifics. Like is the black or white wire supposed to be the power?

23026

[geezer101]

They are expecting you to add a pressure switch off the oil filter mount (like the idiot sender for the dash oil warning light). Personally, I wouldn't bother. IF I had the option, I'd use a safety switch like the OEM ones that kill the ignition in the event of a roll over. Otherwise a manual override switch somewhere in the cab would be a good call IMO (if it backlights to let you know it's active, it'll stop you from having a psychotic episode when the engine won't run lol). Whenever I've installed an electric pump I've added one into the centre console.

[pennyman1]

there is a thread on how to wire in the oil safety pressure switch - it is good insurance, as it also will save the motor if you lose oil pressure while running...

[85Ram50]

Long day. I got the mount built anyway. I won;t have to even undo any part of the vent line. I cut off those mounts and welded them to the new pump mount. It goes in there fine. I'll have to search that oil pressure switch. I think all I need now is to work out which is the supply and which the return in the engine bay I'm pretty sure I can do that :) Then get some wire connectors and run a wire. I'll take suggestions on the path to run the wire please. Here is a picture of the mount.
23043

[85Ram50]

I think I found it Pennyman. It is an article titled - "Fuel Management System:Electric Fuel Pump Installation" Below the instructions it has a copy of several diagrams for different installs. Now I know I can keep this running until I find the safety switch and pipe connections (did you say the motor stock pressure fitting is metric Pennyman?) and figure this out to my own comfort level. Might be nice to have it start without having to pour gas into the carb after its been parked a few days. :) http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=5636&d=1369160634 I will just get an inline fuse for it then leave it in when I connect a safety switch. Wire running route anyone?? :)

OK So

1. 1. Where is the stock oil pressure switch?
The FSM says "The oil pressure switch is located at the center of the right hand side of the engine." The only thing I have seen there is the temp sending unit. I remember there was a wire that used to hang free below the oil filter which I plugged into something there. Is that it?
2. On this diagram http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=5633&d=1369160014 I would think the wire Geezer pointed me to would suffice as the starter connection. What would the wire connected to ignition switch in this diagram connect to? I think the ignition switch is in the steering column so???

EDIT- What a fuse should I use for the inline fuse? I think 10a is as low as i will be able to get.

Fuel Management Systems http://www.mightyram50.net/vbulletin/showwiki.php?title=Fuel+Management+System:Electric +Fuel+Pump+Installation&highlight=wire+safety+pressure+switch


(http://www.mightyram50.net/vbulletin/showwiki.php?title=Fuel+Management+System:Electric +Fuel+Pump+Installation&highlight=wire+safety+pressure+switch)

[85Ram50]

Can anyone tell me how to wire this Standard Oil Pressure sending switch P133 ? https://www.rockauto.com/en/moreinfo.php?pk=44183&jsn=3
I can get it off the shelf for $6 but it has no markings to indicate what terminal is NO, NC, C

[geezer101]

NO is the 'normally open' circuit (this goes to 12v from the live side of the ignition circuit power), NC is 'normally closed' circuit (this is bridged off the starter motor wire to the starter solenoid - it'll supply power to the pump while the starter is cranking) and 'C' is the common (this one goes to the 12v+ input on the fuel pump which would be the white wire in your pic)

[85Ram50]

OK Geezer. I was mistaken about the wires sort of. The yellow red stripe is correct and the black red stripe is correct but the third wire in that loom is not to the choke, the choke is wired direct to the coil with a blue wire. The third wire in that loom is black yellow stripe to the starter with a female spade connnector. It is only powered when cranking. I have found an Airtex Wells video of the fuel pump oil pressure switch install which is good https://www.youtube.com/watch?v=tPh2Na3vbGc

I bought the Duralast PS122 at Autozone. https://www.autozone.com/external-engine/oil-pressure-switch/duralast-oil-pressure-switch-ps122/123596_0_8537 It does not have the markings on it but they do have them in the online picture. The Duralast marking in the picture align with the P, S, I that is in the Airtex vid. I got the 1/8th pipe fittings and cable ties so I should be good to go and I found a vid on how to T splice wire that seems good to me https://www.youtube.com/watch?v=D4b_gSciGIg
I figure the switch is the one under the oil filter.
So if I understand everything I will run the pump wire directly to the pressure switch P prong, the black yellow stripe wire to the S prong and the black red Stripe to the I prong. I have it up on jack stands and I am done for the day. I did cut that hot wire and put a female bullet connector on it Geezer.

[85Ram50]

Install electric fuel pump 1st gen Mighty Max/D50
There will be links and a vid of an Airtex Install that makes it very simple and will help 2nd gen trucks for inside the frame install. There will also be a link to the page where this website made a page for it. You may be like me and not able to infer or interpret some of that stuff without having to ask a lot of questions. I added a vid for how to T splice wire that I found.
It requires a lot more than just the pump and wire. You need at least a oil pressure safety switch to shut down the pump when the motor quits. Some add in a relay as well. I used Duralast PS122 oil pressure switch. The picture of it on Autozone's website shows which pin is which. They are using the P (Power),S (Starter),I (Ignition) designation just like the airtex vid. https://www.autozone.com/external-engine/oil-pressure-switch/duralast-oil-pressure-switch-ps122/123596_0_8537 Third picture from the left shows the S and I
You will need a 1/8 Pipe nipple. I went with a close nipple. And a 1/8th pipe T. I chose brass for both parts and got them at the home supply store. teflon tape. Don't destroy the OE oil pressure indicator you need it.
You will also need enough wire (min 14awg) to run from the driver side of the engine bay to the fire wall across, along the other fender and down the harness past the alternator twice. And a dead run from the pump to that same spot. I went along the frame rail inside using the abandoned return line to attach with cable ties. Then up the backup light harness and across the firewall.
1. I removed the OE oil switch and installed the nipple and T. You get some oil which quickly dries up to a drip. I went with the middle of the T and put the sensors into the T on either end. I used teflon tape and after starting the nipple I put the T on it and used the T to drive the nipple in. Then I put teflon tape on the old sensor and the new one had pipe dope on it so I did not bother.
Airtex Wells install video https://www.youtube.com/watch?v=tPh2Na3vbGc
2. In the driver side engine bay there is the temp sensor with a yellow wire with red stripe on it. Follow that back to the harness, there will be two other heavy black wires (Mine are red and yellow striped respectively) coming out of the harness. One used to plug into the Mikuni it should be hanging free, the other goes to the starter. You can run from the end of the free one.[EDIT-if you have the Mikuni still you can T off this wire END EDIT] That goes to the I position on the oil switch. You T into the other heavy black wire and it goes to the S post on the oil switch. The other post gets the wire from the pump. The wire to the starter is only hot when cranking. The other one is hot as long as the key is on. No Solder wire T splice video https://www.youtube.com/watch?v=D4b_gSciGIg
I then removed the fuel pump and capped the return line up front. I ran from the main supply line to the Weber. I had to move the inlet nipple to the other side to make it easier for me. I made a cover for the hole in the head with the same sheet metal I used on the pump mount. I have the plastic spacer and a new gasket. I used red gasket maker too. I had to get shorter bolts, at autozone they are M8 x 1.25x 25mm I think.
(Zoinks do you know to remove the skirt? You need to get access to the bolts on top which are inside the interior panel of the bed. I had to drill out the screw in the panels and the bolts.)
You can see my mount allows all the original equipment to stay in use. I cut off the connectors and welded two to my mount the other one for the filter I cut the steel off the nut and just used it behind the mount plate. I started with that style mount plate becuase the one that inspired me to try was designed in that shape. Then I started cutting it to suit my needs.
After I got everything installed and hooked the battery back up it runs great. I left it idle while I took it down from the jack stands. No issues yet.

Electric fuel pump install complete.

Sorry about the blurry pic of the oil pressure switch but I am showered and not interested in getting dirty again :)
23052 23053


Fuel Management System:Electric Fuel Pump Installation
http://www.mightyram50.net/vbulletin/showwiki.php?title=Fuel+Management+System:Electric +Fuel+Pump+Installation&highlight=wire+safety+pressure+switch




(https://www.youtube.com/watch?v=D4b_gSciGIg)

[geezer101]

^that is how you do a write up :thumbup: The pump mounting plate is nice too but I'd do something about the wiring for the pump (I think it needs to be routed in-board and sheathed in something to protect it personally) So, if you compare the PS122 switch with the Airtex vid, the wiring is 'NO' (normally open) = 'S' for the starter motor wire, 'NC' (normally closed) = 'I' is the live ignition power 12v+ and 'C' = 'P' for power 12v+ to the fuel pump. Easy as!

[85Ram50]

Hey Geez, I thought I had messed something up at first because the starter sounded so different. But it started after the third try and I liked how it was running. Then it hit me that extra always hot wire that mechanic connected to the starter was driving it a lot harder than it should want to go. I bet this improves my gas mileage too.

[pennyman1]

Sorry I didn't respond sooner, have been busy with a kitchen remodel. Looks like you got it working though - good job!

[85Ram50]

No Worries Pennyman you left enough bread crumbs I was able to work it out. :) As I recall not the first time you have saved my bacon on this truck. Lets not forget Geezer's invaluable assistance either.

[pennyman1]

We both try to help where we can...

[geezer101]

You're welcome :thumbup:

[85Ram50]

I'm glad you guys liked it. It still gave me trouble because of the engine running hot. The oil pressure would change enough it cut off the pump intermittently and I'd have to push in the clutch and rev it up to get more gas from the pump while lurching.
I have changed the set up today 5-30-24 to a relay fuel pump wiring kit from JDM performance Parts on eBay. They literally have a diagram and labels on each wire that tells you where to connect it. Even I could not screw it up.

Edit 5-31-24- I may have spoken too soon. It won't start and I only hear the pump turn on randomly when cranking. I am doubting what I posted above here as well since it seems I have the black red stripe spliced so it powers the starter solenoid and the black yellow stripe going to the blade connector on the starter. I wonder if my wires are just so dang rotten that is the problem? I have had issues with my dash gauges working or not working randomly since i bought it. I am currently trying to figure out where I can tap into a key on power source other than that black red striped wire. Or it could be the relay wiring kit not working well??? It seems solid and the wires are all 12g or better.I think the ground might be 14g. ugh
Edit later in the day- So I rested then went back at it with a multi meter. Un-taped that splice I made w/o a connector (link above) and could not really get a consistent reading there. But I did trigger the relay several times. I figured that splice might be breaking the connection since I was connected up the line of it to my key on power source for the pump relay. So I crimped the two wires on one end and the other one the other end with a butt connector and when I turned the key the pump came on and stayed on and it fired right up. Off and on several times and it seems OK. We'll see tomorrow. It seemed OK yesterday when I took that nice drive in the hills.