2001 jeep intermittent misfire.

[90xj06]

Originally Posted by RetEBoogie

Also the tach is kinda jumpy when it misfire.

how jumpy? like sharp drop to 0 and pops back up? you might be losing the crank signal completely. check to make sure the wire isn't melted or shorting on the exhaust.

[RetEBoogie]

So I got off shift today and decided to check the ECU or PCM due to the randomness of the misfire. I've attached some photos of the only thing I found. There was some corrosion under the circuit board in one spot. Any idea if this would alter the functions of my ECU? Well now I can figure out how to post the photo lol.

[Rob Mayercik]

You'll need to upload the photo to a hosting site like imgur or flickr, then you can put a link to it here in the forum.

[RetEBoogie]

So a little up date on the xj. I have replaced the ECU, crank, cam, ignition coil, the connector to the coil, inspected the engine harness, synced everything, and I still have a miss fire to the point I'm unable to drive the jeep at all. It is completely intermittent sometimes it runs fine but 90% of the time it runs like crap. I've scoured the site for any info and have done everything I have found to do or check. The code is intermittent loss of cam or crank and coil circuit A above or below threshold. I'm at a loss and need a little help before I junk this thing. Appreciate the help in advance.

[RCP Phx]

Originally Posted by RCP Phx

When my 2000 started having similar issues, it was the wiring cross-shorting between cylinders and eventually took out one of the drivers in the pcm.

Have done a megger test on the wires?

[RetEBoogie]

I'm unfamiliar with the test you speak of.