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My r33 gts-t backfires at high rpm when backing off the gas... pop pop pop i have re-gapped my plugs to .8mm too and it didnt happen before that so im guessing its got something to do with that...

Not to sure why but yeah..

M

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  shoebox said:
According to what I have read so far, misfiring can shorten the turbocharger's life drastically (damage to the turbine blades) and place the entire exhaust system in shock.. it doesn't sound very good.

This doesnt sound good...

Instead of starting a new thread - Does anyone know how to suppress backfiring?

Is it just a matter of tuning or is it usually something more sinister - eg cat?

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  shoebox said:
According to what I have read so far, misfiring can shorten the turbocharger's life drastically (damage to the turbine blades) and place the entire exhaust system in shock.. it doesn't sound very good.

your talking about antilag aka missfiring system

Primordial is talking about something else

sounds very normal, nothing to worry about. its a case of running a stock ecu, too much fuel, hot exhuast and this creats backfires or pops, it is more common on warm days because ur engine wiill be hotter along with everyother part in ur car

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Thanks Michael,

This sounds correct.I'm running a PFC so it mustn't be tuned properly? How exactly to you lean out mixtures when throttle is dropped off? This isnt really possible with PFC is it?

Its sounds right though... it just a hot exhaust and too much fuel..

Great for scaring pedestrians tho :(

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My 34 also does this a little bit but its more of a babble gurgle light popping than large backfireing. It did this straight after a power fc and tune. What bov are you using a atmo one will cause backfires.

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if the tune is lean on decel it can do it also. i had a pop at idle due to a vacuum leak, which was making the car run lean.

but just having a big exhaust usually adds a slight pop since when backing off air is trying to force its way back up the exhaust.

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Dude do you run a atmo BOV, or do you have a recirculated one. a while ago i had to replace the headlights on a cop car due to my atmo BOV, thats when i was told to put the stcok recirculation system back on and is misteriously dissapeared. oh yea and i run a big exhaust 3.75 inch straight back with 1 resonator, no cat and a muffler in the end, and i dont pop. have it cheked it might safe you a engine build due to turbo failure. :yes:

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my guess is the problems is caused by blocking the BOV the AFM puts in fuel for air that isnt there. causing a backfire.

try using your plumb back again and see if that helps.

also look for any intake leaks after the afm,

an aftermarket ecu which removes the afm will solve this and much more.

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  NISSANR33GTST said:
my guess is the problems is caused by blocking the BOV the AFM puts in fuel for air that isnt there. causing a backfire.

try using your plumb back again and see if that helps.

also look for any intake leaks after the afm,

an aftermarket ecu which removes the afm will solve this and much more.

that's actually wrong... the ECU only dumps in more fuel when your using an atmospheric BOV.... if you've blocked your BOV, all the air still remains in the system and the correct air/fuel mixture is obtained.

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  johnnilicte said:
that's actually wrong... the ECU only dumps in more fuel when your using an atmospheric BOV.... if you've blocked your BOV, all the air still remains in the system and the correct air/fuel mixture is obtained.

he is running an aftermarket ecu, so it doesnt matter.....!

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