Fuel Pump!

Hey guys, I'm working on my project 1986 comanche 2.8 swapping a 1996 4.0L with ax15 and matching transfer case. The current gas tank does not have an integrated fuel pump since the 2.8 was carburated and had a mechanical fuel pump. Now I'm wondering what would be the best options.

I was thinking maybe put an inline electric fuel pump close to the tank, turning it on with the key.

I've kept the gas tank from the '96, with a (should be) working fuel pump, only thing is, the guy put a hole in the tank to drain it.

So my options are basically, fix the tank and switch, or install an inline.


If I go the gas tank swap route, I need to figure out the 5 wires (shouldn't be too hard) and weld/patch the hole, I was thinking JB weld.

Please give your two cents

Does no one have an opinion on this? Would an inline electric fuel pump work out? I really feel like going this way and leaving the current tank on the truck, well attached and plugged... I guess I'll tell you guys if it worked or not.

if i remember right the Comanche uses a tank mounted on the left side inside of the frame.the Cherokee uses a rear mounted tank and i know the tanks wont swap.the 96 uses a returnless system and i believe you will need at least 44 to 52.5 psi. you should be able to do use a good pump mounted to the frame. i would find a used tank instead trying to patch. yes i have had some sucess with JB weld on an aluminum tank in a old jet boat.

I would buy a tank from the junk yard MJ with the pump in it and have it factory

Comanchedude said:

I would buy a tank from the junk yard MJ with the pump in it and have it factory

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I would, but there is none around!

I found some with higher pressure rates (65 psi)

http://www.summitracing.com/parts/ATX-E8445/
http://www.summitracing.com/parts/CRT-P74015/

Some are cheaper but they claim 40 or 45 psi max... I have not found any specs on the engines injector (haven't spent hours looking for them I admit) so I'm looking for something in the range of 45 to 55, I'm just afraid 45max might not be 45 all the time or barely enough? I have a week to think about it, can't buy it before the paycheck comes in.


Spending some time searching
1987-1990 53003956 Black 39psi 18.6lb/hr
1991-1993 33007127 Brown 39psi 21.0lb/hr
1994-1995 53030343 Tan 39psi 21.0lb/hr
1996-1999 53030778 Grey 49psi 23.2lb/hr
1999-2006 04854181 Blue Tip 49psi 22.5lb/hr

The only spec the service manual gives is that it should not drop below 35 psi within 5 minutes of being off and 49.2 +-5 psi when the pump is on. However, they say if you have 54 psi (which is 49+5 in the spec) then the regulator is bad. Chrysler is weird.... In one breath it's ok, but in the other it's not.

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I have a 1984 Cherokee XJ and upgraded from the 2.8L boat anchor to the 3-4L. The 2.8 engine has a mechanical fuel pump while the 3.4 engine doesn't and needs an electric fuel pump. You can mount an in-line fuel pump that turns off when the engine stops where ever it suits you. A very good idea for those elderly cherokees that remain carbureted is to have an additional fuel filter with a fuel return outlet to the fuel tank mounted just before the carburetor to re-circulate the fuel back to the tank. This helps keep the electric fuel pump cool and avoids vapor lock.