popping under decel

[ca18det240hatch]

ok, coming down from 4k rpm, 3k, whatever, when i downshift and come off throttle, as the revs are coming down its popping and fluttering out the exhaust. im not having problems with acceleration really, just that sound at decel...is it normal? anybody else have it? I have a megan racing downpipe, testpipe, and hks catback, no resonator tube by the look of it.

ideas?

[Liquid_Neon]

mine likes to pop a lot too, specialy if i leave it in gear and motor brake. I always figured it was cause i run kinda rich at idle?

[ca18det240hatch]

yah thats when mine does it, when im motor braking....maybe i just need to put a resonator in.

[mbmbmb23]

ok, coming down from 4k rpm, 3k, whatever, when i downshift and come off throttle, as the revs are coming down its popping and fluttering out the exhaust. im not having problems with acceleration really, just that sound at decel...is it normal? anybody else have it? I have a megan racing downpipe, testpipe, and hks catback, no resonator tube by the look of it.

ideas?

Is your BOV atmospheric or recirced?

[ch187]

is it really that bad?

[nissanic89]

poppin like a backfire , it could be a bad maf or at least that what a friend told me, mine did on a engine brake slow down thingy thoe

[Indecisive]

mine does it too. nothing severe, but if you know what an engine should sound like, you notice it.

[ch187]

do you mean decelleration? haha nice terminology buddy.

[Liquid_Neon]

poppin like a backfire , it could be a bad maf or at least that what a friend told me, mine did on a engine brake slow down thingy thoe

And tuesday my maf died... maybe it was on its way?? that at least would make me happier then thinking it just up and died one day.

[ca18det240hatch]

i am vent to atmosphere. It doesnt leak, i know that for sure. And it doesnt just go rich when i blow off, thats not a problem, only engine braking. its like a series of small backfires in a quick succession.

doesnt do it when its cold, only when its warm i noticed.

[Indecisive]

do you mean decelleration? haha nice terminology buddy.

deceleration

[bone_stock_240]

Do you have a blow through maf setup? because if you are venting atmospheric, than you will run a bit richer when you let off the throttle.

doesnt do it when its cold, only when its warm i noticed.

well that would make sense. When your car is cold, the exhaust temp isn't hot enough to ignite the unburnt fuel from you running too rich due to the atmospheric vent.

Unless I am not thinking about this the right way.

[ch187]

deceleration

wow..you lose. **** spelling. its the ****ing internet

[bone_stock_240]

do you mean decelleration? haha nice terminology buddy.

wow..you lose. **** spelling. its the ****ing internet

settle down hypocrite.

[Indecisive]

settle down hypocrite.

thank you for getting my point

now...back on topic...

it seems this is a normal symptom...or is it just that many of us have it but shouldn't.

[ch187]

i didnt give a hoot about his spelling.

Quote »engine brake slow down thingy [/quote]im a hypocite, sue me.

[ca18det240hatch]

Just had my friends heavily modded sr20 out today, same thing, his farts and putters coming down in teh rpms during decelleration

[Turbogeek]

you're injectors are not firing on decel so:

compression firing (engine braking) + 3" dp + "test cat" + full exhaust = some backfiring and popping sounds

[Turbogeek]

oh and it is to be expected with your set up, there's nothing to be worried about

[ca18det240hatch]

just to explore this further out of curiosity, why is it that happens.....

is it raw/un-ingnited fuel in teh exhaust lighting up because the pressure isnt blowing it out anymore?

very curious about this one...always wondered. My rx7 turboII backfired like a MOFO under decel.....