jeepkiller

Changed both sensors still have problem. It might possibly be a timing chain any advice?

J20jeepster

I am also getting this code.. I was about to replace the sensors.

kjc

Tripdagoat just posted about his fix..
Had a CEL for as long as i've owned my 4.0L ZJ. i was getting code P1391. driving me crazy trying to clear it. replaced both sensors. back probed the entire wiring harness. replaced the entire ignition system. Nothing. So after some advice from a seasoned Jeep mech, i replaced the entire distributor. apparently they are prone to wear that is enough to cause the code. It was super easy to do which was nice since i did it in the autozone parking lot to avoid the 75 dollar core charge. the distributor only runs 50 bucks. You will need a phillips head screwdriver to remove the distributor cap and a 1/2" wrench to get the distributor off. Just make sure you pay attention to how the old one comes out and be sure to put the new one in the same way. Long story short, the CEL is finally gone!!! I had searched and searched for the answer to this problem, and from what i can tell NO ONE has tried this to correct the issue. If this works for you, please pass it on to all jeep owners that may have this problem. This would have potential to be a very expensive repair if going at it with no ideas.
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Dub

Hacker777

Solved!!

First time posting.
Had the same problems (CPS and CPK Codes) rough idle or no start. Read posts, here and other forums. Was going to re-replace (distributor style) Cam Position sensor but decided to garb hold of the tone spinney thingy that the sensor senses. (Don’t do this while it’s spinning). I thought to myself “Hmmm that’s odd…. this spinney thing rotates freely. This is supposed to be, directly, geared to the oil pump / crankshaft” I then decided to pull it out….”Clink clank clunk” The small gear that was on the Cam position sensor shaft dropped into the oil pan.

The spring pin that holds the gear to the Cam position sensor shaft had sheared off. Once I got the gear out of the oil pan and replaced the whole assembly the engine worked fine.

I think the intermittent nature of the problem was due to friction between the gear and the shaft. Once the shaft got spinning, the sensor was able to pick up a (poor) signal.

Hope this helps.