1990 XJ ign. cont. mod. or what?

I have a 1990 XJ (my 2nd jeep) and im having a weird issue with the truck. The jeep always starts on first turn, sometimes, i can drive it for a hr and no issue, sometimes it will drive for 10 mins and then shut itself off. Normally after it shuts off, i can throw it in park and restart it with a little bit hesitation and a moderate amount of cranking, but it seems to be getting worse in the "restarting" area for some odd reason. It is a high mileage truck, and im not sure what has been replaced on it untill i took over ownership.

Has anyone had a problem like this? my first thought was a ignition control module, but when i seen the price tag of $150 for it, i was wondering if there is something else i should check. Im replacing the check engine light this week along with 10 other dash pannel lights but was wondering if someone could share their expertise with me. Your help is greatly appreciated.

before it shuts off does it sputter at all?

No sputtering what so ever. Just seems to shut off intermittently.:helpme:

I have had a CPS go bad, when it would get hot it would quit working and shut the engine off. Just a hunch

The Jeep would always restart but only after 10-15 min or if I poured a bottle of cold water down over the bell housing and cooled it off.

Not saying this is the cause but Joe Peters has mentioned this in the past, and I performed it as maintenance on both my Renix Jeeps. Unbolt the coil from the ICM. Clean up the pins/contacts on both pieces so they're shiny. Pinch them a little tighter and add some dielectric grease. Bolt it back together. Best case, you fix the problem. Worst case, you won't have a problem later with connections in that area. Takes about 10 minutes to do if you're really slow.

migsyx said:

Im replacing the check engine light this week along with 10 other dash pannel lights but was wondering if someone could share their expertise with me. Your help is greatly appreciated.

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I would hold off on changing any of the electrical stuff untill you could diagnose you starting and running problem. Once you start digging into your other wiring stuff you could create more problems making it harder to pinpoint anything electrical in nature.

Check out my original post on my similar problem for a bunch of tips from others helping me chase my problem.
http://www.naxja.org/forum/showthread.php?t=1031953

Similar post with tips:
http://www.naxja.org/forum/showthread.php?t=1034039
http://www.naxja.org/forum/showthread.php?t=1038851
http://www.naxja.org/forum/showthread.php?t=1037125

Get it to a fault condition, then check the resistance of the crank sensor--200 ohms + - 75 ohms.

Intermittent issues are always a pain.

After checking the crank sensor, do the other "free" things: grounds are critical for the Renix. There is one OEM unibody ground--braided strap at the driver's side rear of the head to the firewall. I recommend replacing it with a 4 or 2 gauge cable. There are CRITICAL grounds at the dipstick tube--the ICM, ECU, o2 sensor and others. You need to strip all grounds down to bare metal, treat the metal with anti-corrosion agent, and make the connections TIGHT.

Service the ICM/coil clips as Cruiser54 mentioned--corrosion on those makes for some interesting intermittent problems.

So, get it to a fault condition and test the crank sensor, then grounds, and the ICM/coil contacts.

Post up what you find.

Good luck.

I think you scared him away, Joe.

cruiser54 said:

I think you scared him away, Joe.

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Darn, and I had my Happy Face on too! :wierd: