P1391 cam or crank sensor
#1
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Model: Cherokee
P1391 cam or crank sensor
Alright just bought this jeep trying to get it smoged but check engine is on. 98 xj 4.0 auto. 186k. Jeep runs absolutely fine. It was throwing this code and a p0112. Iat sensor. Replaced the iat sensor and crankshaft sensor. Lost the iat code but the crankshaft remains. I've been reading to replace either the distributor or the PCM might be fried. The only reason I care is to get that damn light off so it can be smogged but it runs fine. Any input advice or ideas
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alright so I have done a bunch of research on this and it appears to be a very common problem. however everybody that is throwing this code seem to be having problems with the jeep running bad and/or not starting. in my case however the jeep runs like a top, no rough idling, no sputtering, no hesitation...nothing. now I have already replaced the camshaft positioning sensor, which I later found out everybody suggest mopar oem, however I bought the autozone duralast, but the jeep still runs fine. upon replacing it I drained the computers memory and started it back up. no light, drove about 50 miles, drives exactly the same. light came back on same code. now in my knowledge of cars, not jeeps in particular, if a camshaft sensor or crankshaft sensor goes out it runs like *****. this is why I am reaching out. please help!
#3
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Year: 1995
Model: Cherokee
Engine: 4.0
That code can set if your distributor is not sequenced correctly, or if the air gap for your CKP sensor is incorrect. The CKP sensor should have some type of spacer on it to set the correct air gap, also but less likely the trigger wheel for the sensor could have a couple damaged teeth. Good luck and happy diag buddy
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ya that's why I have read to go with the oem ones...idk im at a losson this one. I just want the code gone so I can smog it...gonna take it to my buddies shop on Wednesday. ill post the culprit when discovered. im tired of sinking money aimlessly
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alright guys I haven't heard of this one or read about it but the problem ended up being the sync between the camshaft sensor and the crankshaft sensor. simple adjustment to the distributor and problem fixed!!!! got rid of that pesky code and passed smog
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I was not present at the time he did it. But there is a small bolt like a 12 or 13mm underneath the distributor he said he loosened that up and gave the distributor a small tweak and tightened it back up. He said he had to do it a few times until he got the position correct. I never knew such a thing existed but he's been an ase certified mechanic forever so I'll take his word
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