Ok I'm new hope someone can help. I have a 2000 xj I keep getting a missfire code p0301 cylinder one. I have put new plugs in with a coil rail, cleaned the IAC checked for vacum leaks. If I dissconect the battery for 20 minutes it clears the PCM and it will run perfect for about 5 ignition cycles, and if the check engine light is off at cold start it will run rough again and the light comes on same code. I also have run seafoam through the intake and in the gas tank please help. Thanks