Backfire After Service

[JVP]

hey dudez

just had my major service completed the other day

i had replaced:

timing belt

water pump

cam seals

spark plugs

fuel filter

now when just cruising around, i change gears and the car backfires, not really loud but has never done it b4. when i really give it a boot and change gears it is quite loud. now i have the car booked in to get a dyno tune and was just wondering whether this will fix the problem. and the car has always been out of tune a bit so im hoping this will get rid of it. it has always backfired on decellaration too, which i wasnt worried about.

mods to the car are 3" turbo back exhaust, FMIC, pod, bov and boost to 12psi.

thanks for your help in advance guys

cheers

jabba

[mad082]

what plugs and gap were put in? are you running stock bov or atmo? if it is atmo bov then that is the problem and its nothing to worry about. my car used to do it with the stock bov till i put new plugs in then it went away.

[GTAAAH]

Maybe its just running a lil richer since you had the service done.. Check your plug gaps as mad said, that should help, but i think almost all rb20's backfire anyway, they all run pretty rich

[JVP]

i used nissan genuine plugs, they supplied them.

i just thought its wiered that i have replaced everything with new and now its doing it. never did it b4...

im not worried really but its rather annoying when u give it a boot, my car sounds sick.... lol

thanks for your help dudez

its a turbosmart bov, so thats atmospheric yeh?

Edited August 2, 2006 by JVP-R32

[mad082]

its a turbosmart bov, so thats atmospheric yeh?

it depends. does it have a big hose coming off it? is it loud? if it doesn't have a hose then its atmo, so that would be the the cause. as to why it never did it before, who knows.

[JVP]

yeh it has a silicone hose coming off the end

i think its a type 3...cant remember...

would a dyno tune help, im getting it done regardless, but when they fidle with the fuel and timing when they tune it, could this repair the problem? im getting an ecu chip done very soon also. when they replace the timing belts, does the tune go out of whack? sorry im a n00b at this.

thanks guys

[linxus40]

less you have an aftermarket computer a dyno tune will do nothing as you cannot change the fuleing or timing of a stock ecu without remaping it.

Edited August 3, 2006 by linxus40

[JVP]

then what exactly does a dyno tune do?

[GTAAAH]

Adjusts your timing, checks your hoses, cant think of much else

Oh and it will tell help you see how much power your cars putting out and will help see the condition of the motor

Edited August 3, 2006 by r32 gts-turbo

[JVP]

ok, adjusts timing. thats what i said b4....

is there a possible chance that this backfire is a timing issue?

[mad082]

if it was a timing issue the car should be running worse in general.

[JVP]

i feels heaps more responsive since ive had all this shite changed, its just the backfiring when changing gears that just annoys me...

ahh well i will see on monday how it goes....

[d00dz]

Its just running rich? ie. the R&R that normally occures with std ecu? 12PSI? on std turbo everyday? damm

My car backfired heaps when I did a few more mods to it and uped the boost. It would backfire every gear change, every downshift, I was even able to make it backfire on demand. Off throtle and on throtle etc..

Sometimes it would backfire by itself 4times in a row! "ZOOOM POP POP POOOP POP"

You shouldnt have anything to worry about, just means car uses more fuel, and the cat might be rooted lol

[JVP]

i dont drive it everyday. only weekends now and only maybe once during the week.

the cat is brand new, only been on for a couple of months.....

[JVP]

car still back-firing, new fuel pump installed (bosch 040)

plugs were genuine nissan, which cross referenced to PFR6A-11, as recommended on here....

could it be the coils?

the pop is really loud, can feel it in the cabin lol

just need some help, its doing my head in.

cheers guys

[Links]

When is it happening.. coming onto boost.. or when you back off boost..

Is it happening ALL the time, or only after you have been giving it a bit of a run..

If it's a) backing off boost & b) after you've been giving it a bit - the excess fuel is just being ignited as it hits the turbo/exhaust causing it to pop.. not really a huge issue..

Not sure why you'd get a "Dyno tune" when the car has the stock ECU.. unless you think there is something seriously wrong I don't see the point.. unless you want to see how rich your A/F ratios are going..

Not sure how a new fuel pump will help..

Hmm.. trying to think of what else it is.. more details on when it happens would be good..

[JVP]

happens when changing gears, no matter how hard or soft i drive it. so off and on boost i spose

just had an ecu chip and new fuel pump installed due to being running overly lean.

[JVP]

bah, still back-firing!

time to check coils?

i dunno.

[Mr. Oizo]

bah, still back-firing!

time to check coils?

i dunno.

misfiring or backfiring?

backfiring is from excess fuel igniting in the exhaust

misfiring is from coils or plugs

[JVP]

loud, bang/pop

when cruising, boosting what ever....