I have a '96 2.5L 4cyl 2wd that will start but will not run or idle. Thinking it was a fuel pump issue, my son swapped the fuel pump for the new one he had to go on his 6cyl 4wd. The physical fit is perfect. My question is this: Would the 6cyl 4wd pump be compatible with the 4cyl 2wd vehicle? Do you think that the fuel pressure or mix or any other issue would cause the 4cyl 2wd to still not idle or run? I can't seem to find this answer anywhere. I just need to get this thing running and I am at a loss. Thanks in advance for your help and guidance!

 

Go to a popular auto parts website like ROCK AUTO. Enter in the specifics of your vehicle and then look at the range of engines a fuel pump will work on to see if there is a different application for the source of the donor pump.

Note that 96 was a year of change for the fuel systems for the XJ. The early 96 had a fuel pressure spec of 31 and the later 96 XJs have a fuel pressure of 49 psi, plus or minus 5. There would definitely be a different pump for these two very different fuel delivery systems.

If there is any question after ensuring you have the right pump installed, test fuel pressure under the hood. It's easily done; rent a gauge if you don't have one and see where you are at.

If the new pump exhibits the same symptoms as the other one, you likely have a problem other than the fuel pump. Scan the computer with a code reader or scan tool to see if there are any codes or pending codes. Review status of tuneup hardware; when was the last time you changed plugs, plug wires, distributor cap and rotor. And always consider battery condition. Have your battery "load tested" at any parts store; it's free. A marginal battery can and will give you symptoms including stalling at idle.

Good luck and keep us posted!