So another problem that came to haunt me recently. 94 XJ 4.0

Have a problem when letting the jeep idle, it feels like it starts to load up. It will pop through the intake, but shows no codes. I can lightly throttle up and eventually power through it and clean it out. When driving its fine. Let it idle it will start to run progressively worse.

New crank sensor, 02 sensor.

I havent tested fuel pressure yet. I seached and found a few things,but mostly on OBD2 systems. Any of these symptons ring a bell to a problem you've had before?

 

Ran it for almost an hour with a fuel pressure gauge hooked up. Finally it started running bad fuel pressure went from 31 to 20 psi. I put a spare pump in from my 92 and its running good. I see that the pump from a 92 is different then a 94. Anyone use a diff year pump in their XJ? Think ill be ok?