Hot restart issues

2000XJ
35K (really!)
Stock engine. Exterior mods for the sand.

Got a strange one and I haven't been able to learn anything about it doing normal searches.

Jeep runs fine most of the time. The only time there's an issue is when I attempt to restart 10-15 minutes after running at normal operating temp. The 10-15 minutes is critical. 5 minutes or 30 minutes and it's fine. It acts similar to a choked engine back in the carb days. Real rough idle and sometimes it won't start at all until I let it cool some. No codes.

This has been driving me and my mechanic crazy. We tried a number of shotgun fixes but nothing has hit the problem. This vehicle is fairly new to me, but I know and trust the original owner and he says no heat shields or anything have been removed.

Any thoughts?

Thanks in advance.

temp sensor? Had the same issue a few months ago and turned out to be a bad temp sensor...

There is supposed to be a metallic heat shield blocking #3 & #4 injectors to prevent vapor lock, is yours intact/missing?

Thanks for the replies.

I'll check for the #3 & #4 heat shield tonight after work. Vapor lock. That's sounds right. Acts like it's choked but there's no fuel smell.

Temp sensor.
Dumb question. Is there any way to test it other than swapping it out with a new one? I have normal tools, meters, etc....

There is a TSB on this,

TSBs... Thanks!
Sure describes the problem.
Can't find the details... guess I need to call a dealer.

If anyone is tracking this, here are one's I found:


· TSB #1803903 -- ROUGH IDLE DUE TO HIGH AMBIENT OR HOT SOAK TEMPERATURES. THIS CONDITION MAY BE MOST NOTICEABLE WHEN THE ENGINE IS RESTARTED FOLLOWING A 10 TO 20 MINUTE HEAT SOAK IN HOT AMBIENT CONDITIONS OF APPROXIMATELY 32 DEGREES C OR HIGHER. *TT (NHTSA ID #10005644, NOVEMBER 14 2003)
· TSB #1803103 -- 4.0L ROUGH ENGINE IDLE AFTER RESTART FOLLOWING A HOT SOAK. *TT (NHTSA ID #10003986, SEPTEMBER 05 2003)

let us know how this turns out....that is what the solution ends up being...

I had the same problem with my 2000 XJ...ended up doing a homemade version of the TSB...just wrapped each injection with adhesive backed aluminum tape...

As a followup, I ended up getting some heat wrap from Summit Racing and wrapped all my injectors. Seems to have cured the problem.

Thanks again for the help. :cheers: