The problem began with intermittent stalling and now the Jeep will not start at all (no spark). I have had the cap, rotor, primary ignition coil, crank sensor, cam position sensor and PCM replaced without any luck. The repair bills have been brutal. The garage has given up.
Hey Tester … sorry, I did not get a notification about your response. I will check into it. I appreciate your suggestion. This is one of the few things that I have not tried. Thanks again …
Has the shop actually done any diagnostics on this problem or has it been a shotgun approach?
There are a number of fuses involved in the EEC operation and someone may have egg on their face if the problem is caused by a simple blown fuse.
Another possibility is a failing anti-shutdown relay which also operates through some of those fuses and which provides power to the coil, PCM, and so on.
I think it’s time for a different mechanic. A competent shop with the proper equipment should be able to diagnose this in less than half an hour. Ask your friends, neighbors and coworkers for a recommendation to a local independent shop, then ask that shop if they have an actual scan tool that will “talk” with your car.
Thanks … I appreciate all the thoughts … I should have given more details.
The Jeep has been in three shops for these problems over the past year or so (depending where it broke down). Each one has kept it for at least several days. This last shot at it has been nearly a couple of months now (no kidding). Each shop has claimed that they have run all the diagnostics which don’t show a problem. The shops then tried the “most likely” replacement. The Jeep runs fine ( a sweet running Jeep is so nice ) for a while … sometimes months and then the stalling / starting problems reoccur. I was told that once it stopped being an intermittent failure, it would be easy to track but no luck. I could tow it to another shop but I will first ask about the pickup coil on Monday. It seems like everything else has been replaced at least once (ouch).
Ahh, it’s an intermittent. Some thoughts about that:
Your car is old enough that the engine computer may not store any valuable info about the no start condition. The only way that I will guarantee a diagnosis on something like this is to have the car in a consistent no-start condition. If it may go months at a time without acting up any repairs are just a shot in the dark. But if the truck will not start while at a shop with the proper equipment it should be simple to find the trouble.
You say no spark. We also need to know if there’s fuel pump operation and fuel injector operation and proper voltage to the engine sensors at the time it won’t start.
You may need to call your Jeep dealer and find a parts guy knowledgeable about such “ancient” systems but some Jeeps had a crank sensor patch kit. Jeeps are very sensitive about crank sensor input, and the Cherokees had a “patch kit” that bypassed the engine wiring harness and connected the crank sensor directly to the engine computer. Not sure if this applies to your car.
The fuel (pump and injector) was checked and does not seem to be the problem. I was told that the voltages are good too. The car now is in a consistent no start condition but no luck on the diagnosis. I called a (distant … local folded) Jeep dealer but they did not have an idea except to retry / retest previous repairs. The dealer or the garages did not mention this crank patch kit. I will try to look into that too. I will call another dealer once I have done some homework.
I went to check out the Jeep in the garage. It did start a couple of times (and ran well) but the third time, it was a big no go. We talked over all the suggestions posted and he showed me that they had all been tried (cam sensor / distributor coil, relays etc. … at least once with the exception of the patch kit)
I hate let it go for unknown causes but we are out of ideas.
Thanks again … any further suggestions would (also) be appreciated.