jeepster10000

Hello, and thank you for taking to time to read my post...I have a 1999 Jeep Grand Cherokee that I have had for a few months the body has 200000 miles on it, but there was a reman motor put in, but I am not sure how many miles are on the reman I would have to look through the paper work to see. When I first bought it it seems to run just fine no hesitations or anything, but a few days after that I took a trip into town came back shut off the truck a couple hours later I went to start it and it just turned over...Ill try and give you the history and details to try and narrow down what may be wrong. So I got it into the garage and started checking the obvious stuff, what I found was that there was no spark, so I bought a used computer and a used engine harness for cheap but in good working order...after a while of trying to trouble shoot, I took it to my mechanic and he found that the crank shaft position sensor was bad, when he put that in he said he was able to get spark, but when he tried to start it, it would run but it sounded like it was miss firing or out of time. He checked to see if it had jumped timing, it hadent. So now he is leaning toward a flex plate that has shifted?? does this make sense, or would it be more of a sensor problem...? What I would like to know is should I cut my losses with this guy and find someone else to help with this issue? I would really like to pay him and get it back to the house and fix the issue myself if anyone can assist me with this issue. Again thank you for your time and advise.

Bustedback

Replace the cam sensor

CrazyMacaw

I don't know how a flexplate would shift unless maybe it broke off, warped, or the end of the crankshaft got bent.
If any had happened I'd think it would be very obvious. A warped one or bent crank shaft would give a mechanical vibration when running and possibly an inconsistent CKP pulse which should set a code.
If it had broke off you wouldn't be able to start it....heheh
I'm curious, if you diagnosed it as a no spark situation why was your first choice a used (not remanned) PCM and wiring harness?

Is it presenting any PCM codes?
Is the spark consistent with the new CKP sensor?
It's hard to say for sure without more info but if he thinks something has shifted I'd look at the CMP sensor and/or it's alignment for a misfire condition. Alignment is a quick and easy check - just a screwdriver and a toothpick, and is much more probable then a shifted flexplate.