mis fire with no codes.

which means no shop can help me.


My 1996 XX 4.0 aw4 will sometimes misfire for some reason. it happens when i am mostly on the trail and right after i turn the jeep on after a break. It will misfire for about 5 min the run fine. My comp only through a code once and it said that cylinder 4 was running lean and misfiring. What would be the cause of this?


I have ruled out:
spark plugs: since it only happens sometimes, I would think a fouled plug would always misfire)

New wires: I bought new wires thinking maybe that was the problem

new dis. cap(that also didnt fix it)

and i though possibly a fuel injector but that should cause a problem all the time right?

any other thoughts? also my comp stop throwing the code so it reads clean now :skull2:

Don't rule out either spark plug or fuel injector as cause. Intermittent problems are alive and well in XJ'sville. If you have set a code for a particular cylinder, I would focus on all things associated with that cylinder. Spark plug, spark plug wire, fuel injector, cylinder condition itself.

Start by installing a new plug (or an entire set if it's been a while) in #4 cylinder. Alway simple things first and can't get any simpler than installing a new plug. If that doesn't help, swap the injector in #4 to a different location and see if the code (which will probably eventually set again) follows to the new location.

If that doesn't help either, run a compression test on #4 and a couple of others minimum and see what you get.

http://www.wjjeeps.com/tsb/tsb_wj_1803103.pdf

Check out this link...you may want to do this to all of your injectors...

injector heat soak, i had the same issue in my '96. wrap the injectors with the heat insulating sleeve-i used thermotec heat wrap-that should take care of it.