Hey guys. This problem just started about 2 days ago where when my engine is warm if i stop at a light or stopsign my car will idle rougher than normal than when i accelerate softly my car wil backfire until it gets to about 2000 rpm and it will just accelerate normally. I havent done anything except put gas in my car and wash it for the last month so i dont see anything that would have made this start happening. Btw my car is a basically stick 75 280Z.

Thanks, Jason

Is it backfiring out the intake or the exhaust?

Is it backfiring out the intake or the exhaust?

AFTERFIRE = exhaust

BACKFIRE = intake

AFTERFIRE = exhaust

BACKFIRE = intake

Not everybody uses that nomeclature, so it is better to ask than to assume.

Not everybody uses that nomeclature, so it is better to ask than to assume.

The use of incorrect nomenclature during technical discussions is a sure fire way to have misunderstandings.....! Just trying to pass along a bit of info to help the misinformed.

FI or carbs?

My car does the same thing.... is it when you start to give it gas it sometimes (not everytime) sputters and backfires as you give it gas, then does normal (sometimes loud) backfire on deceleration?

the car is fuel injected and from what i heard tonite coming home it seemed like afterfire from the exhaust

come on guys i really could use some suggestions here

If it's coming out of the exhaust, you have too much unburned fuel in your exhaust. This can come from running rich, a weak spark, or wrong timing to name some possibilities.

I know this is an old thread. But it the issue is similar to mine. I have 75' 280z, it hesistates on acceleration until about 2-3k and it will accelerate normal again. I'm getting backfire in the intake. It all started happening after I installed an ebay cai, and msa headers. The header bung is closed, but the EGR is still open, not sure if this will cause these kind of symptoms.

Things changed: fuel lines,vacuum lines, regrounded wires, intake couplers, spark plugs and wire.

The car has ran perfectly fine before the installs.

Any help is appreciated.

oh its fuel injected.^^