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 ??

as it is..jpg

[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.