I've had some problems with a rough idle after an extended idle, or high speed driving. I shut the Jeep off at Haspin this summer, and wasn't sure it was going to restart. Here is some info I've come up with in case anyone else is having this problem.
I went down to my friendly Jeep dealer and this is what I learned. Oh BTW they WON'T supply the part OR install it for free. It cost me $8.07.
Subject: 4.0L Rough Engine Idle After Restart Following a Hot Soak
Overview: This bulletin involves the installation of a fuel injector insulator sleeve.
Models: '00-'04 TJ '99-'04 WJ '01-'04 WG '00-'01 XJ
Applies to vehicles equipped with a 4.0L engine (sales code=ERH)
__________________________________________________ _______________ Basicly is says 20-30 seconds of rough idle after a restart in hot 90* or higher.
" This condition may be caused by heat from the exhaust manifold that following engine shut down migrates to the area around injector #3 and cause a fuel vapor to form within the injector. This in turn may cause a momentary misfire of cylinder #3 until the fuel vapor is cleared of injector #3. The insulator sleeve lowers the injector temperture to a point below which the fuel will not normally vaporize."
Insulator sleeve part #56028371AA Ignition Wire Shield
It says this part will make 2 injector insulator sleeves. __________________________________________________ _______________
Another Service Bulletin # 18-039-03 involves reprogramming the PCM to lower the temperture at which the electric fan kicks on. My past experience with reprogramming a PCM was a cluster f**k to say the least. It cut the MPG of the '96 Dakota I had by 6-8 mpg. So I'll leave this one as a last resort.
Hope this helps anyone else that has this problem.
thats good to know, i knew mine did that a few times but kust always figured heat and those damn injectors on the same side was the problem, had that problem with an older ford with the 300l6 in it, vapor lock, fuel system wise. would give me all kinds of fits. Ill just deal with it, not much longer, getting ready for new intake/bored throttle body and a ceramic coated header install!
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MY happy place is dark, so YOU cant see the scary things!
Well I've been working some crazy hours so I just made it out to the Jeep Dealer today to pick up the part I ordered.
The part is a 6" piece of what appears to be white insulated split wiring harness cover. You cut a piece about 1" to 1 1/4" long and wrap it around the #3 injector with the split up. Then cut another piece and wrap it around the other with the split facing down. Pretty simple, but I needed a break afterwards.
$8.07 for a 6" piece of this stuff is expensive. If I can find something like it I might just insulate the other 5 injectors.
