Cracked solder joints are becoming a major issue for OEM electronics.  The mandates to remove lead from the solder leaves the new stuff brittle.  It just doesn't heat up and flex over and over without snapping.  Definitely really check that.  More of an autopsy than surgery I think, but I'll be interested to know if you find anything glaring. 

Thanks for satisfying my curiosity on the plugs!

I bought a reman alternator from them for my truck because they were the only place that had one in stock, and it was a lifetime warranty.  Its now been replaced under warranty twice in two years.  I'm remembering the scene from Tommy Boy where he asks the customer why someone would put a guarantee on the box.  "Because they know all the sold you was a guaranteed piece of #$%^.  Look, if you want me to take a dump in a box and mark it guaranteed I will; I've got spare time.  But for now, for your sake, for your daughter's sake you might want to think about buying a quality product from me." 

This thing fails again I'm getting my money back and splurging on the DC Power 185 amp upgrade.  Should have just done that first, but couldn't wait 2-3 days to get it.

TKOPerformance wrote:

I bought a reman alternator from them for my truck because they were the only place that had one in stock, and it was a lifetime warranty.  Its now been replaced under warranty twice in two years.  I'm remembering the scene from Tommy Boy where he asks the customer why someone would put a guarantee on the box.  "Because they know all the sold you was a guaranteed piece of #$%^.  Look, if you want me to take a dump in a box and mark it guaranteed I will; I've got spare time.  But for now, for your sake, for your daughter's sake you might want to think about buying a quality product from me." 

This thing fails again I'm getting my money back and splurging on the DC Power 185 amp upgrade.  Should have just done that first, but couldn't wait 2-3 days to get it.

I must be lucky.  There is a place here in Auburn that rebuilds generators and alternators.  I've used them a couple of times with good results.  But Norcal is a long way from most of you.
 

It wasn't the PCM.   Tomorrow I will take the airhorn off for the third time and finally do the plugs that have been in there 8 years and the Cops and see those results.

I can't say for that model specifically, but 0.65" plug gap doesn't seem too wide for a coil on plug system.  We used to run 0.55" with a simple HEI, and would often to go 0.60 on Fox cars with a Screamin' Demon coil, good TFI module, and good wires.  Most coil on plug systems are throwing 80,000-100,000 volts compared to those other systems which were in the 50,000-65,000 range.  I'd verify what the gap is supposed to be before assuming its incorrect. 

Here is the final update.  After changing the plugs and coils it is now running great!  No misfires.  Took it for a test drive and i felt confident so I drove my wife to the store in it.  I am sitting in the parking lot now.  I declare the problem resolved.    Spark plug gap was supposed to be .040.   They were well worn.  Seven of the 8 coils were still factory from 2004.  One I replaced back in 2012.  The one I had replaced is the one that smells really bad like burnt electronics.  So maybe it was causing issues with the others???  Jeep electrical wiring is very redundant and all the grounds are tied together.  Bottom line is it's running, and I guess this is a lesson learned, to always check the basics...never too old to get a lesson!

TKO called it!   He was right.

Last edited by Greg B (3/06/2021 12:30 PM)

Cylinder #4.  I think the main culprit.