Anyone know what can cause this??? I put a nitrous system on, but it happened before I sprayed the motor. The only thing that kind of went wrong was fuel noid got stuck and flooded the motor causeing some backfire, but car was fine after this. I changed the plugs to tr6's gapped at .035 for the nitrous. Drove the car about a thousand miles and then it started his misfire stuff. It happens when the car is started. It misfires bad throws engine light and then a few 15sec later it is fine until I start the car again then same thing all over again. I changed plugs and checked wires thinkin maybe that was it. Still does it. When changing the plugs the drivers side had wet oil all over them. Mostly on the threads nothin in the electroide part. Anyone have any idea where to check next? I was thinkin pull the valve covers and see what it looks like under there??
Thanks

 

pulling the valve covers will probably not give you any clues, perform a compression test