mustangdave357

If you open up the gap on the plugs too far could that possibly cause a misfire? I have an occassional pop through the airbox that the ford garage said was definately a misfire in 1 or more cylindrs. The check engine light will come on but then go right back off. They said they couldnt pull any codes unless it stayed on. The car sat a long while and they seem to think its just condensation in the tank. What else could possibly cause a misfire? I just put on motorsport wires and a motorsport dist. cap and rotor kit, changed the plugs and fuel filter. Someone suggested the fuel filter might have been put on backwards, the car wouyldnt even start would it? thanks, Dave

roundman

yeah too big a gap could cause a misfire
fuel filter being on backwards shouldn't cause a car not to run in most cases, it just will shorten the life of the filter in service.
what year and what engine are we talking about?

mustangdave357

1995 Cobra 35,000 Miles The parts store said a 54 thousandths gap was best. Maybe I should have left the the 45 the came out of the box

roundman

if they are missing at the .054 gap, something else is wrong with your ignition as it was designed to fire the larger gap to get a bigger spark for better performance. go through your whole ignition system and check out all the pieces/parts to find out what is weak or bad and then the problem will go away.

VertStangGT86

If you think condensation might be an issue then get some gas treatment to get rid of anything that might be in there, or just run it down and refill it with good/new gas.

mustangdave357

Thats what I am trying, I bought some dry gas and filled the tank up and started driving yesterday, I just dont want to drive if this is a serious problem. when the car runs good the tach climbs nice and smooth, when the popping occurs the tach jumps and goes up but its not smooth at all. I am hoping this fresh tank of gas fixes it, any other ideas?

mustangdave357

Well put a set of motorcraft plugs in with less gap, 45 thousandths and not 54 and still the pop, guess I will drive it and see if there really is water in the gas from it sitting