Fuel Pump Replacement


Parts Collector
NAXJA Member
1988 2WD MJ 4.0L w/5spd.

The fuel pump hasn't quit (yet) but is noisy and when starting both hot or cold has a drawn out cranking time before starting. Years ago with my 88XJ it was the fuel pump check valve allowing fuel to drop back into the tank & pressure to drop.

I crawled under the MJ and saw the sender unit is mounted into the tank side not the top and wondered how low does the fuel in the tank need to be before removing the sender unit?

1/4 tank? 1/8?


New member
1/4 tank or below is fine.

The sending unit is dumb big in there. pull the shaft to avoid having to wrangle it around and risk damaging the sender.

If you pull the shaft it will come up and straight out, super easy.


New member
Didnt need to take the drive shaft off on ours, not a big deal for access.

On ours the Fuel gauge sender was bad but could not find an MJ one so I modded an XJ sender to work on the MJ pump mount.

Used a hose clamp to hold the fuel pump, and some screws to hold the XJ sender after trimming the mounts. It barely fit.

The dumb parts store pump came with non submersible hose so had to do the the same dance the next weekend. Same thing happened to me with my XJ pump like 15 years ago.