Hey guys still fighting this problem where my jeep will run fine if it cold but once it starts to warm up it will buck like crazy then stall. If I go to start it, it will crank fire then die immediately. The longer I let it sit and cool off the longer it will drive for once it's started. I have replaced fuel pump and filter, cps, cleaned the iac motor and did a full tune up. Some where I read it might be the distributor so I put a test one in and it still had this problem. Any ideas?

 

Ignition coil is next up on the suspect list. In my opinion, the coil is the #2 cause of thermal (heat related) failure on the 4.0

You could try testing resistances on the coil when it is symptomatic or just swap in a different coil. You need to rule it in or out.

 

Forgot to type that. But it's new

 

when it dies whats missing fuel or spark?

 

Ever checked codes even if theres no light on ?

 

Change the sensor on the thermostat housing

 

If u unplug it jeep won't start at all friends jeep was doing that change the sensor ran str8

 

You need to do some "quick" testing when it is symptomatic. Let your XJ warm up in your driveway until it's symptomatic, then start testing.

Start with spark. Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground and have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark.

If you have good spark (and only if), then try a small shot of gas into the intake and see if it starts using that strategy; that would confirm a fuel problem.

Below is how to check for codes as freegdr mentioned. Very easy on your vintage. The coolant temperature sensor can cause starting issues with a hot engine as already mentioned.
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Retrieving OBD codes on the Jeep Cherokee (XJ) OBD1 Models: 1991-1995

1) Start engine (if possible). Move transmission shift lever
through all positions, ending in Park. Turn A/C switch on and then off
(if equipped).
2) Turn engine off. Without starting engine again, turn
ignition on, off, on, off and on within 5 seconds. Record 2-digit
fault codes as displayed by flashing MIL.
3) For example, fault code 23 is displayed as flash, flash,
4-second pause, flash, flash, flash. After a slightly longer pause,
other codes stored are displayed in numerical order. When MIL begins
to flash fault codes, it cannot be stopped. Start over if count is
lost.

NOTE: A "5-5" will always occur to signal the end of the sequence. Some will flash the "1-2" code indicating a recent battery disconnect even if you haven't done it. Ignore these two codes, and mark down all others.

 

Besides what Mr walker is suggesting, and making sure to ignore the "my friend's Jeep got fixed by throwing this part at it" suggestions, take a peek at the fuel pump ballast resistor on your driver's side inner fender. Connecotrs loose? Is it getting real hot?

Got a volt meter? Check the voltage at each side with the engine running

.

 

Have been flashing codes and nothing ever comes up. Ran with a fuel pressure gauge hooked up and stayed at like 33 the whole time even when stuttering. Figured I have spark sense it will fire. I will look for the fuel thing in drivers fender.

 

I don't think I have a ballast resistor. Also replaced o2 sensors and the sensor on the thermostat housing.

 

I don't think I have a ballast resistor. But also I have replaced the o2 sensor and the sensor on the thermostat housing

 

I think you do. 33 is low fuel pressure BTW.

 

Hmm well I will look again in the morning, I thought my pressure was supposed to be around 31?

 

U learn stuff the hard way. I figured I try in help not to get bashed on. If the op didn't need ideas on what was going the thread wouldn't of been started.