i have a 97 Jeep Grand Cherokee Laredo 4.0L In-line 6 that had been giving me numerous problems, including stalling. i ended up adding some grounds to the vehicle as well. i had a bad IAC valve that led to a faulty O2 sensor and fouled plugs. my fuel was running too lean as well. i have changed my O2 sensor, plugs, and IAC valve. i also changed my ECT ( engine coolant temp. sensor ), my CPS ( crankshaft position sensor ), my coil, my distributor cap & rotor, my camshaft position sensor/ pick-up / relay, and my plug wires. electrical system is great. fuel system and it's pressure & delivery are great as well. the Jeep runs and sounds great. here's my problem. the Jeep cranks up & warms up just right. i drive everywhere i got to go around town. after i get home and the vehicle sits for a couple hours, it will turn over but, not want to crank. about the 3 try it will fire right up and run for about 5 seconds or less, then die. no dragged out stalling or sputtering. just go dead. i plan on using my voltmeter to check voltage on the TPS ( throttle position sensor ) & the MAP ( manifold absolute pressure sensor ). don't understand how they work fine all day and then suddenly fail though. could the ITC ( intake temp. control sensor ) cause stalling like this? just curious what someone thinks it could be. it would seem like it would have to be one of these 3 sensors causing this. everything else is new and functioning properly. appreciate any help.

 

I'm afraid you'll have to wait awhile for someone a little more knowledgable, but have you tried changing the ASD relay? It's possible it's weak and not holding in after a heat soak. Try swapping it with the AC relay or a headlight relay. You've tried everything else.

 

This is kind of out there, but are you running fuel with ethanol? My ZJ stalls out when it is warm in the summer when I'm running ethanol after I drive it for a bit, but has been just fine in the winter running it. There is only one gas station in my town that doesn't have any ethanol in it and is subgrade fuel... like 83 octane. I started running that this summer, and have had no issues. Maybe that could be it??? Sorry, shot in the dark....

 

I read on alldata that higher grade fuels can cause running issues. I use vpower and i have no issues. Not sure which models it effects though. I got a 98 zj 4.0 4x4 early model

 

ever think about checking for codes ...