Hi there,

Trying to figure out this issue with my wifes Cherokee. It's a 1996 4.0L 4wd Auto with ~150k.

Throwing code P1391 - Intermittent loss of CMP or CKP. I have already swapped out the cam and crank sensors, but still getting the code.

I am going to look over all the wiring tonight, but is there anything else that could be throwing this code that I should look out for?

Thanks.

 

I assume your talking about an XJ?...i would say the only other thing would be the computer but i have heard with XJ's it could also be a timing issue.

 

Yeah, I have heard similar. How would I go about checking the timing?

Thanks.

 

Had the same problem with my truck for about 6 months now and just now figured out how to fix it. I had replaced both sensors, checked the circuit, and replaced most of the ignition system, and nothing. had a jeep mechanic give me this advice and it worked. I replaced the distributor, the whole thing, shaft and all, and the CEL is gone! apparently these are prone to wear and its just enough to cause the code. the distributor should run you about 50 bucks, but you will probably have to pay a 75 dollar core charge. i replaced mine in the parking lot of autozone so i wouldn't have to pay the core. Yes, its that easy. you will need a phillips head screwdriver and a 1/2" wrench. pay attention the distributor position on the way out and be sure to put the new one in the same way. they should also have the code reader to reset the code. Let me know if this fixes your problem.

 

I replaced the distributor and still get the code.

 

I am having similar problems and have been doing a lot of research. Where did you get your sensors? lots of folks are saying that for sensors you should go to dealer as the XJs don't seem to like the aftermarket sensors. Also some folks have had problems at the connections, sometimes just wiggling the plugs on and off will improve connectivity of plug or there is a cleaner you can buy to better clean connections too. If you have a multimeter you can test the functionality of the sensors you have (I don't personally know the process, but I know it can be done)

 

Don't ya just love girls with Jeeps?

 

personally I'm looking for a man with Jeeps. lol

 

I really liked this*information.