bad miss fire?

I have a 90 inline 4 and it has a bad miss fire. When the jeep is cold it runs like a champ. when it is warm and i stop and turn it off then back on it has a super bad miss fire. i thought it might be a plug or something so i changed the plugs, wires, cap and rotor. i am at a loss and its killing me. if anyone has any ideas please let me know what you are thinking. oh i also checked all the vacuum lines and i have no vacuum leaks. please help if you have any idea. thanks for the help guys.

Mine had the symptoms you describe last year and recently have begun again. The first time I found that the IAC was coated in black, sooty carbon and was sticking. I cleaned it up and she's run fine until the last few days. I will check it today and clean it again. I'll post back what I find.

Search;

Carbon seafoam.......after a good cleaning, if you still have issues...

search cracked head'
Ya, you know where I'm going with that one........good luck with the seafoam.....

When you say "miss fire", is this a popping noise out of the intake or exhaust, or is this just a roughness showing that a cylinder is missing? When you changed the spark plugs, were they all the same color? Were they light tan, brown, black, oily, etc.?

all the plugs were the same color when i changed them. it is just a miss fire no poping sound.