I've read through all the posts I could find on the engine misfiring but mine is a little different.. Not that it couldn't still be the plugs or plug wires.

08 auto with 15k miles that only does it with the a/c on.. Started while we were up in Ouray Colorado. Thought I got some bad gas so I ran some injector cleaner through it. That seemed to help some but it still gets an occasional miss or stumble.. Get it off idle and it's fine..

Not sure if the altitude made it worse, or the injector cleaner helped..
Air Raid air cleaner doesn't look all that bad but I'll get it cleaned this weekend.

Thoughts?

 

Been running fine down here in Denver.. An occasional miss but nothing major.. Was back up at altitude last weekend and it was as bad as ever..

Going to change out the plugs this weekend. Next weekend we're back up at altitude.. I'll see if anything changes.. If not, it's off to the dealer..

 

if it only happens when the ac is on maybe it doesn't have as much power as before? Bad batt or possibly a bad alt. Let us know if the new sparkers fix the problem...

Also check for a good seal on the intake for the air.

 

My 2006 TJ 2.4L did the same thing. They replaced the computer and it still did it....only when the A/C was on. It was a big problem in the later TJ's...
Marc
2008 X

 

Does it throw any codes? I get p0300,mult engine misfire about once a month, I put in fuel injector cleaner and seems to help for a bit.