backfire

**Jorrs** · 03-01-2006, 06:46 PM

hey guys sometimes my car backfires. from 2nd to 3rd gear, it happened once when was under a bit of load i was giving it a fair bit into 3rd ? anyone no why this occurs ?
cheers

**sam-131** · 03-01-2006, 07:03 PM

whats your car/engine has it had a re-tune recently
sounds like a mixture of bad timing and poor tune

**Yian** · 03-01-2006, 07:05 PM

AFM and atmo-venting BOV combo?

**Selk** · 03-01-2006, 08:43 PM

wat is backfire.... explain plz

**sam-131** · 03-01-2006, 08:45 PM

the engine back fires loud pop or bang maybe a flame shot out the exhust can be caused by a few things

**Selk** · 03-01-2006, 09:02 PM

cool, like timing....more

**takai** · 03-01-2006, 09:02 PM

Could be a leak in your exhaust manifold, that quite commonly manifests on sudden close of throttle.

**Selk** · 03-01-2006, 09:16 PM

could it b incorrect combusten (mixture of fuel & air) in tha chamber

**Jorrs** · 04-01-2006, 12:54 AM

the motor is 3sgte 1st gen, in a st162, and yeh i did have a venting BOV put on it recently, though it doesnt really work

so how does the BOV make it backfire ?

**Yian** · 04-01-2006, 12:56 AM

Guessing by the 1st gen 3sgte, it'd have an AFM? With a venting BOV, when shifting, the ECU still thinks that the air is still within the system (but its not due to the venting BOV) hence it runs uber rich.

Uber rich = backfire

**Jorrs** · 04-01-2006, 12:59 AM

yep its AFM, well that makes sense, will it cause damage ? should i remove BOV or plumb it back ?

**EldarO** · 04-01-2006, 01:39 AM

get rid of the BOV altogether.

basically the car thinks its getting alot of air, which it isnt, and dumps fuel into the engine, the fuel goes straight out the exhaust ports because theres too much for it to all burn, and ignites in the exhaust, hence the popping.

Eldar.O.

**UMP-man** · 04-01-2006, 02:38 AM

i'm running an atmo bov on my gen2, and i havent noticed any side affects at all.

**4DaDrift** · 04-01-2006, 11:20 AM

Edited post.

**Smokey228** · 04-01-2006, 12:00 PM

u can destroy ur cat, unburnt fuel goes shooting down ur exhausts and explodes. see you bye cat...

my car has no cat, and backfires on a regular occurence, so provided my car doesnt explode and kill me im happy... but im not spending money on no 18rc...