Misfire when hot, replaced everything I could think of... Options

[cv7713]

OK, been chasing a misfire for quite some time. The car runs great first thing in the AM but misfires once normal operating temp is reached. Misfires at idle and while driving. First, I have replaced all fuel and ignition components and all vacuum lines. I decarbonized the combustion chamber (MOPAR CC Cleaner, good stuff!). I have replaced the MAP sensor, O2 sensor, and some various wires that looked corroded. Stock 5s-fe.

The engine bay seems to be getting extremley hot! (but not overheating). Yesterday I pulled the plugs to see if they show any evident signs of wear and I was confused by what I saw. The firing end looked great (brown to grayish color), however the insulator on top of the plug was brown and blistered (burnt)?! Anyone ever see this? They are NGK plugs with the factory heat range. Also (not sure if this has to do with the misfire) but every now and then I hear a pop come from my gas tank. Is the "pop" just releasing pressure from the tank? Is it supposed to do that? Sorry so long, I am just truly stumped!!

List of parts replaced:
Fuel Pump, Filter, Pressure Reg, Charcoal Canister, EGR Valve, and injectors
Brand new distributor, wires, plugs, igniter, O2 sensor, MAP sensor, and even the ECU!

Could this be a bad cat causing the heat? Cracked head? Thanks for input...

This post has been edited by cv7713: Nov 9, 2007 - 11:21 AM

[supradog1]

i think i know what the problem is!!!! "a failing altanator!!!" i will prove this theory tomarow when i can put the altanator on a test bench but i think its the cause of the misfire... reasons why: #1 when i have the car up to runing temp and have no a/c or radio on the car has no misfiring (or at least its very rare) then when i turn on all my goodes(a/c, radio) the car starts misfireing like a m/f!!! reason#2 driving in normal cool weather with no goodies on car is fine, i drove onto southbeach and got stuck in traffic to see what happens when it gets hot with no goodes on and as i thought, it started misfiring more and more the the hotter it got... because the alt is is old and week the hotter it gets along with all the extra current draw from a/c and radio is causing it to start to fail and the warning sighn must be this misfire!!!