• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Convert 97+ To External Fuel Pump?

j-dubya

NAXJA Forum User
Location
Atlanta area
Poking around the web and not seeing too much on this. I’d like to get the fuel pump and filter out on the frame for easy service and replacement.

Has anyone been down this road before? Anything to consider with the OEM pickup and sending unit?

Thanks.
 
It's easier to just cut a access hole!
 
That is on my option list, yes. Just having done in-line stuff on buggies and diesel trucks, I’m curious what the hold back is for it on later XJ’s. Being right there on the frame is good for diagnostic checks too.
 
There are a couple of downsides to an external pump: Lack of cooling and noise.
 
Consider installing an early tank, Early tanks like my 1990 have the pump access hole on forward wall of the tank, meaning you have access to the access hole without having to drop the tank. Should be straight forward, and you get the stock pump and level sensor. for the early tanks the filter is mounted on the frame external to the tank.. Wiser minds may tell ypu if the old tanks fit in the new xj's

Are you having troubles with short fuel pump life? Perhaps using a bad brand of pumps or maybe contaminated fuel or crud in the tank?
 
ps make sure the new pump is correctly wired to shut off when ignition is off, engine stops turning, or timed. so wire it using the stock wires. if you wire it say simply to the ignition switch, you wont have the automatic shut off feature that is so important in crashes.

fuel pump safety circuits include ecu control such that the pump is cut off when engine stops turning, even if ignition is left on, other system use a g force switch to sense impact for shut off, other have even used oil pressure as the trigger to shut off the pump. so make sure your install does not bypass the safety shut off feature, or if so, install you own safety feature to automatically shut off the pump.
 
Consider installing an early tank, Early tanks like my 1990 have the pump access hole on forward wall of the tank, meaning you have access to the access hole without having to drop the tank. Should be straight forward, and you get the stock pump and level sensor. for the early tanks the filter is mounted on the frame external to the tank.. Wiser minds may tell ypu if the old tanks fit in the new xj's

An old style tank should fit fine. The challenge will be in the pump assembly and sending unit.

Since late model XJs do not have a return line you would need to run a '96 fuel pump assembly as it is the only year of the old style tank which has the pressure regulator on the pump assembly. That part used to be unobtanium, but I believe someone like Crown now makes a reproduction.

The next issue would be the fuel level sending unit and its compatibility with the late model fuel gauge. I believe the old style operates at a different range than does the late model. If the variable resistor (the plate which is swept by the arm inside the tank) could be swapped that might solve that issue. You would need to look into that and probably run some tests.
 
Are you having troubles with short fuel pump life? Perhaps using a bad brand of pumps or maybe contaminated fuel or crud in the tank?

No issues with the pump, but it’s on the list to update as I go through the Jeep. I have no idea if it’s 22 years old or has been replaced before, so as I go along replacing stuff, I prefer to update whatever it is if it helps dealing with it again in the future. A typical frame mount system would be much easier to deal with in every scenario.
 
Back
Top