Ignition Control Module

[mujaman]

well i've been having the same problem now for about 4 months, and still have not been able to narrow down what exactly i need to replace. i've made a few other posts about this... but basically my jeep is having a problem where it will "stall" after i've been driving for about 45 min. or an hour. it doesn't ever die and the engine doesn't miss or stumble... it just cuts off the acceleration and goes down to idle speed and has absolutely no throttle response for a few seconds... then kicks right back on as if i floored it. it does that on and off constantly until i stop, turn it off for a minute or two, and start back up. then it runs fine for a while. it seems like it has to be some component overheating... but i don't know which one. i replaced the ignition coil a while back, although i really didn't think that would fix it, it was easy and i thought i'd give it a shot. well, it didn't help. i'm guessing its gotta be the ICM, but i don't know where that is on mine (97 cherokee 4.0). i've heard from some people that its somehow built in to the vehicles computer, other people have said its down inside the distributor, and my haynes manual says its somewhere near the ignition coil (or atleast thats what it sounds like its trying to see... it gives a rather vague description). so... provided i'm on the right track and the ICM is the culprit, where is it and how do i go about replacing it. i suppose it could also be a fuel problem or something with the distributor cap or the pickup inside it, but i doubt it. it never has any trouble starting up (hot or cold) and never actually dies. any help would be MUCH appreciated!

 

[XJNick]

Hi,

Have you verified that your Throttle Position Sensor (TPS) is working correctly throughout it's range. It is a potentiometer so you'd have to test it from Wide closed throttle to WOT to verify it is actually good.

As for the Ignition control module, I know for sure that the older Cherokees use an ICM which is mounted to the Ignition coil and is integral. The post '97 cherokees could be different, though. I'd doubt that it would be part of the Powertrain Control Module (Computer), but am not sure.

-Nick :!:

 

[mujaman]

i haven't looked into the TPS yet, but i will give it a shot. as far as the ICM being part of the PCM... i was just going on what a guy at advanced auto told me. i had gone to purchase a replacement ICM, and the sales rep told me the computer said it was integrated into the PCM and was not a part they carried or something like that. he seemed a little confused himself... so who knows. i'll probably just try to get under the hood tomorrow and look for myself to see if i can figure out whats going on. thanks for the help.

 

[mujaman]

just checking to see if the signature works...