2ndgearhero

Hey all,

Here is my problem:

I have a 99 XJ, 4.0l, Manual with 198k and over the weekend I had a no start situation. Not a problem, I pop started it and was on my way. When I got it back home I did some digging and scanned it. 3 codes came up, 2 for the Crank Position Sensor and 1 for the Throttle Position Sensor. So I replaced the crank position sensor and she fired right up. I drove it for 3 days with no problems starting up but it was throwing codes for the Crank Position Sensor again, but would fire up just fine.

Cut to last night, I go to start it again and no start! Just cranks and cranks but no start. Scanned it again, and again CPS codes. I tested the sensor and the computer, I have the 5 volt constant when the key is set to "on" and I have continuity through the sensor. Still no start.

Could there be something on the flywheel that is interrupting the magnetic characteristics of the sensor? With the weather as cold as it is right now, could it be weather induced? Combining these 2 ideas, I would rather not climb under and take the inspection plate off the bell housing in this cold for nothing! Any ideas? Thanks in advance!

xjmachine

where did you buy your cps from? if its a cheapo aftermarket like duralast it could still be your problem. many of those are known for out of box failure.
faulty pickup coil under the distributor could also cause this

2ndgearhero

I bought the CPS from Pep boys but tested it and it functions fine. I am leaning towards the coil now because I just re-scanned it and I am getting a P0340 code

Roler

This might help
http://engine-codes.com/p0340_jeep.html

2ndgearhero

Just an update here:

Took off the distributor cap and the pickup coil. Filed down the face and the jeep fired right up. Going to be replacing the coil with dealer coil. Additionally I am getting a funky noise coming from the bell housing every so often... has anyone ever had a problem with their flywheel like this???

Roler

Define funky...

2ndgearhero

bit of a whirring, chirping noise. Went away after the jeep warmed up though so....

I think I am just being paranoid!

Roler

Well, you could check the flex plate and especially the bolts. But that's all I could kinda advice regarding bellhouse noises..

PDEM87

Wouldn't hurt to check your bellhousing to engine bolts. Not to long ago, someone on this forum, found the bolts had backed themselves out creating some strange noises.