[firehawk]

First of all the Jeep drives fine. Only when I have driven awhile, and the engine is at normal operating temperature do I have a problem. It dosen't do it all the time, but is becoming more frequent.

After a long drive, or sitting and idling for awhile if I shut the engine off, and when I restart it it seems to be running on 3 cylinders. Once I liked to never get it to start, but only once... so far. When I can get the rev's up it seems to clear itself out and it runs fine until the next time I shut it down after a long drive, or extended idling.

It has set no codes that I'm aware of. Just curious as to what is causing this before I spend some change on O2 sensors. MAN they are proud of them, WheW!

[BeachinXJ]

No. this is a common problem with 00 and 01 XJ's with the distributorless ignition. What's happening is one of the FI's is getting heat soaked and causing a missfire. There is a TSB out on it, to replace a heat sheild to combat the problem... If you do a search there is a lot of info on it.

[firehawk]

Originally Posted by BeachinXJ

No. this is a common problem with 00 and 01 XJ's with the distributorless ignition. What's happening is one of the FI's is getting heat soaked and causing a missfire. There is a TSB out on it, to replace a heat sheild to combat the problem... If you do a search there is a lot of info on it.

Thanks for the info! I'll start looking into it.

[XxpeditionxJ]

Originally Posted by firehawk

Thanks for the info! I'll start looking into it.

Take your Jeep to the local Jeep Dealer and they will install the heat shield for free with no questions asked.

[shierkahn]

I'm having this same problem but, mine's a '92. Still trying to figure it out.

[firehawk]

Originally Posted by XxpeditionxJ

Take your Jeep to the local Jeep Dealer and they will install the heat shield for free with no questions asked.

Well 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.

__________________________________________________ _______________

Service Bulletin #18-031-03 Dated 9/5/03

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.

[toledotimber]

Originally Posted by firehawk

Well 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.

Right. TSBs aren't recalls and the dealership gets to decide if they'll cover them or not (generally not).

[huntsvil]

My 96 has a similar prob too. After idle awhile it starts to stall when I take off. I see this is beginning to be a common thread. Will be watching.

[BeachinXJ]

Originally Posted by huntsvil

My 96 has a similar prob too. After idle awhile it starts to stall when I take off. I see this is beginning to be a common thread. Will be watching.

This is going to be a different problem. Your ignition system is totally different than an 00-01.