2000 XJ sport runs like crap when hot.

[EclipseEgo]

Hello all, this my first post on here. I have a 2000 XJ sport that has a intermittent problem. It seems like it only does it when it gets up to temp and i am doing some running around, stopping at one place then another. Everything will be fine then randomly when i start the engine it will run really rough and hard to get it to rev up. It clears up after a Minute. It did throw some CEL codes for multiple cylinder misfire and misfire codes for cylinders 1,3,4,5 and 6.
I just replaced the MAP sensor(CEL for bad voltage) and i did a tuneup back in Jan or Feb. It kind of seems like something might be getting heat soaked and causing probs, but it doesn't last long enough for me to check anything.

[Cheromaniac]

Your problem is that the injector rail is becoming heat soaked due to the radiant heat coming from the exhaust manifold. The fuel inside the injector rail and injectors vaporizes and the micro-bubbles cause the rough running for the first few seconds after a hot start.
There's a TSB about this issue where the solution is to place an insulator sleeve around the no.3 injector:

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

I have my own solution that's probably even better:

http://www.angelfire.com/my/fan/manifold.html

[bluedragon436]

Your problem is that the injector rail is becoming heat soaked due to the radiant heat coming from the exhaust manifold. The fuel inside the injector rail and injectors vaporizes and the micro-bubbles cause the rough running for the first few seconds after a hot start.
There's a TSB about this issue where the solution is to place an insulator sleeve around the no.3 injector:

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

I have my own solution that's probably even better:

http://www.angelfire.com/my/fan/manifold.html

Hey, Dino.. On those stainless straps you ran to be an extra security for the thermal barrier, did you have them go all the way across the top of the manifold too?? Thinking about going ahead and purchasing the barrier and straps and doing my 99+ IM before I swap it in, along with a new header and motor mounts... Figure never hurts to have extra help fighting the heat monster the XJ's have to fight, unfortunately!!

[Cheromaniac]

Hey, Dino.. On those stainless straps you ran to be an extra security for the thermal barrier, did you have them go all the way across the top of the manifold too?? Thinking about going ahead and purchasing the barrier and straps and doing my 99+ IM before I swap it in, along with a new header and motor mounts... Figure never hurts to have extra help fighting the heat monster the XJ's have to fight, unfortunately!!

Yeah, I wrapped the straps around the manifold on all sides so that even if the glue on the thermal barrier does lose its adhesion, the barrier can't go anywhere! It's worked like a charm and you'll thank me later for inspiring this idea. ;)

[EclipseEgo]

Thanks, I will check into that.

[getterdun]

Curious to hear whether you have been able to solve this?

[jmluperti]

Yeah i had that problem deff heat soaked fuel rail u need to add a heat shield

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