backfire

[fast?]

ever since i tried a colder plug(ngk fr5-1) my car backfires everytime i let off the gas, even when i shift gears. i put a new set of stock plugs in and still the same loud gun shot bang every time i let off the gas.

 

[JonB]

I agree with Tom.

Focus on Plug WIRES and go back to OE Champions

 

[Tom Welch]

Trent,

A couple of questions. Did you burn a plug? Why did you change to a colder one when they are not necessary? How does the car run otherwise? Skip, miss, stumble? You may have a plug wire on the wrong plug. What are the plugs gapped at?

A backfire is the result of unburned gasoline igniting in either the exhaust or intake manifold. Please be more specific with your findings.

Tom

 

[fast?]

i am back to the stock plugs. even the new ones are backfiring. plugs are gapped at 35(should i regap the plugs to 44?). the car runs fine no miss or anything under throttle, but when you let off it backfires. will check plugs again thanks tom and jon.