Excessive Popping/backfire

[delljit]

While i'll admit im no skyline veteran, it does seem that my car is popping more than it should be. I thought it was common for rbs to pop a little but it seems far too often. For starters heres what ive got:

1996 s2 skyline gtst

Mods-

apexi power intake

So as you can see, its pretty much stock. Ive noticed quite a bit of backfire/popping when i ease off the accelerator but thought it would clear up after a service. Well ive just had the coils checked, new ngk iridium plugs put in, new fuel filter as well as an oil change and injector clean. The backfire/popping is still pretty common though.

The fuel im using is shell vpower (98ron). As far as the pod is concerned, it was popping even before i put it on so i cant isolate the problem to the pod making it run rich or whatever.

I had a read through the search function but couldnt find anything specific, any ideas?

Edited September 27, 2007 by delljit

[WRRR]

One possiblity is -

Get underneath and have a good look at your exhaust. Assuming there are no obvious holes if you can see carbon marks at any of the joins you have a leak. On overrun you can get cool air drawing back into the hot exhaust, expanding and thus popping.

Cheers

[r33cruiser]

check ur cat.

when mine was imported, it had a 3" exhaust, but to be complianced had to have a 2" cat.

i replaced it, and about 90-95% of the popping is gone.

the cat was identical to the 3" one. engineer had to actually take it off, and look at the flange and saw the problem

[delljit]

thanks for the ideas, i was going to purchase 3" exhaust system w/ hiflow cat sometime between now and the end of the year.

Ill have to get under and take a close look.

[R31Nismoid]

Whats the timing like?

I would be starting there

[delljit]

Pretty sure the timing was fine, it runs well. Im getting a new timing belt fitted next week, guess ill ask if the timing is ok though just to double check.

[Boosted_33]

hey,

i have also been reading about excessive backfiring,

i have a relative standard r33 series 2

Pod filter + air box

Split dump with 3inch exhaust

9psi boost

FMIC

Standard BOV

I have changed sparkplugs 2 BCPR7ES i always run Caltex Vortex 98. My car only backfires on decel, when the outside temp is hot, i no this sounds weird and crazy but my car will only backfire when it is extremely hot day or i have it on a track.

If anyone has any ideas it would be appricated thanx