Ok so today I started my jeep when the engine was already hot (just under 210) and when it turned over it idled REALLY rough, and then after about 30 seconds of that, it idled normal and had a significant increase in power. I then noticed the check engine light. It ran a little above 210 the whole time I was driving, but ran fine. I'm assuming the code is going to be a misfire, but I replaced the spark plugs about two months ago. So if you have any clue what it might be, I'd love to know. Thanks

 

it should be a cylinder #3 misfire, sounds like heat soak
Edit: http://www.go.jeep-xj.info/HowtoIntakeShield.htm scroll down a bit and this will explain it

 

It was a cylinder 3 misfire, as was two months ago before I replaced the spark plugs. Could I need a new coil pack? I'll read that article when I get home, thanks for it.

 

I've heard of coil packs being the problem, but I haven't encountered that, the gist of the article is insulating the #3 injector to keep the fuel from vaporizing.

 

Ok I think I got it, so the problem isn't my spark plug getting too hot, it's the injector getting too hot!! That makes sense, that article described my symptoms dead on and was very helpful, thank you very much for the help, I'll be fixing that on Thursday.

 

My solution was a new idol control valve and a new o2 sensor. Even new injectors didn't cure things until the new idle control valve was put in.