Weird Popping Noise.

[Shazbanger]

Hey Guys,

Car is a R33 S2, stock bar Exhaust, FMIC and Pod. Today when i was driving, i gave it a little stab, then backed off. It was making popping (backfiring) noises whilst decelerating after that. So gave it another little stab, and it didn't do it as much, but as soon as i put my foot down on the accelerator, even 1mm, literally just touching it, it would make the same popping noise.

It was 37 degree day today, so not sure if that has anything to do with it. Car is due for a 100k service shortly.

I'll take it for another drive later and see if its still doing it, but any ideas in the meantime?

Cheers in advanced for any help.

[Shazbanger]

Still doing it. I think when i pull everything apart to do the timing belt, i might replace the O2 Sensor, get the AFM cleaned, wack a new set of plugs in her, and reset the ecu. Sounds to me likes its overfueling (My old 1JZ Z20 Soarer had a similar problem when we were adjusting fuel mixtures on the Wolf3d) so i'll see how that all goes.

If anyone else has any suggestions, let me know.

[Tony de Wonderful]

Still doing it. I think when i pull everything apart to do the timing belt, i might replace the O2 Sensor, get the AFM cleaned, wack a new set of plugs in her, and reset the ecu. Sounds to me likes its overfueling (My old 1JZ Z20 Soarer had a similar problem when we were adjusting fuel mixtures on the Wolf3d) so i'll see how that all goes.

If anyone else has any suggestions, let me know.

Most likely you are lean which could be for a ton of reasons related to timing issues ,fuel delivery system, intake leak, etc.

Also could be running too rich just when you accelerate then back off the throttle.

Getting boost issues? De-catted?

[Shazbanger]

Hey mate,

Nah, car is running a full 3" turbo back, with cat. No hesitations or lack of power under acceleration. Drives perfect under boost/accel. Only under decel does it do it.

[KEN-R34]

Sounds like normal RB note to me.

[Ten Four]

^+1

Mines doing it heaps now I got a catback on.

Edited November 4, 2009 by Ten Four

[snozzle]

what your experiencing is 100% normal

wen ur foot is "1%" on throttle as u say, during deceleration, the injectors are spitting out a tiny bit of fuel that isnt fully combusting and makes popping noises in ur exhaust coz its combusting there instead

if its still doing it during deceleration, with ur foot fully off the accelerator, ur injectors r leaking tiny drops (possibly from the o-rings or internally)

has your fuel economy changed?

[chubs]

Sounds like normal RB note to me.

this

[Levi_]

Completely normal for a lightly modified skyline, with some light taps of the accelerator on deceleration I can get some decent backfires. Under normal deceleration mine doesn't make to much noise, but because I always hell-and-toe to match RPM when changing down gears it's pretty typical to hear me pulling into slip lanes with a loud series of put-pop-pop-pop-put-pop-pop.

On cold nights with a well timed gear change it's not uncommon to get a decent "fwop!" kind of noise as the fuel in my exhaust ignites.

[Shazbanger]

Took it for another drive, and its stopped doing it now anyway.

But cheers for all the help fellas, muchly appreciated!

[GTR-N1]

Took it for another drive, and its stopped doing it now anyway.

...stopped doing it???????????

OH NO! Now something has gone wrong!!!

lol

[Shazbanger]

...stopped doing it???????????

OH NO! Now something has gone wrong!!!

lol

Hahaha. Thats what i thought.

But in all seriousness, i've been in quite a few RBs, and none of them made this noise. Oh well, she'll be right.

[petern]

I had the exact same issue a couple of days ago(when it was stinking hot)

The car was outside all day.

I found it hard to start, had to actually pump the accelerator pedal to get it to fire up

Would pop multiple times on low de-acceleration (1.5-2k rpm), it drove on boost fine.

Next morning it was back to normal again - I think it was heat soak.

[Shazbanger]

I had the exact same issue a couple of days ago(when it was stinking hot)

The car was outside all day.

I found it hard to start, had to actually pump the accelerator pedal to get it to fire up

Would pop multiple times on low de-acceleration (1.5-2k rpm), it drove on boost fine.

Next morning it was back to normal again - I think it was heat soak.

Excellent.

[mad082]

could also be an exhaust leak somewhere. that is a common cause of popping on decel. a mate of mine had a cracked header in his falcon and it would backfire and shoot flames about 2 foot out the exhaust when he lifted off. was somewhat amusing to watch at night.