I have a 304 Code... w/ intermittent misfire. I have replaced plug & wire. Pulled injector and blew it out and replaced and ran a drop test on 1-4, which checked O.K. Afterwards, drove for about 30 mi w/ no misfire and running smooth. Next morning cranked up w/ miss again. Wondering if it could be trash in fuel rail or what is the likelihood of coil pack going bad? Ideas?
Thewdawg
My 4.6 is notorious for very small water leaks that manage to leak into the spark plug chamber. I would check all the plug wires for moisture.
Coil on plug? If so swap the #4 COP and boot out to an adacent cylinder and see if the code follows it. Look for carbon tracks on the boot.
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