mainly from 1st to 2nd gear i hear a pop from my exhaust...what could be the cause of this?

 

mods?

 

It's a backfire. Any mods?

 

mine did that a lot more often right before my timing belt snapped.

 

Yeah my EG backfires in 1st, 2nd, and 3rd gear sometimes. The cause is probably due to mods like a header, exhaust, and intake. If you are running a test pipe it will always backfire occasionlly. If your not running mods then your engine could be running too rich or too lean.

 

Yeah my car does that too but only sometimes and its not as loud as some cars that I've heard.

^^ Always thought it was from running to rich though??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sifu &raquo;</TD></TR><TR><TD CLASS="quote">Yeah my car does that too but only sometimes and its not as loud as some cars that I've heard.

^^ Always thought it was from running to rich though?? </TD></TR></TABLE>

Nope thats running lean....

 

Could you explain how running lean could cause a backfire. I always thought that running rich would cause unspent fuel to collect in the exhaust which would cause a secondary explosion. Factors such as being out of tune, weak ignition system, faulty injectors or chips with rich fuel maps could cause this also right? Just curious.

 

backfires have nothing to do with running lean...however, a bad air/fuel mixture can cause backfiring but that is usually when not enough air enters the mixture...not too little fuel

 

just i/h/e. i just got my fpr but it was happening before. my fpr's set at 47psi

 

is 47psi a good pressure to put it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shamoo &raquo;</TD></TR><TR><TD CLASS="quote">It's a backfire. Any mods?</TD></TR></TABLE>

Exactly. Try changing your spark plugs/wires/cap/rotor and running sea foam through your engine.

 

i'll try the seafoam thing...spark plugs were actually changed today...new distributor and wires over teh summer

 

don't worry as soon as i put mi I/H/E on my teg it started back firing too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by coronadrinker &raquo;</TD></TR><TR><TD CLASS="quote">don't worry as soon as i put mi I/H/E on my teg it started back firing too.</TD></TR></TABLE>

Did you ever reset your ecu after those installs?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1997GS-R &raquo;</TD></TR><TR><TD CLASS="quote">backfires have nothing to do with running lean...however, a bad air/fuel mixture can cause backfiring but that is usually when not enough air enters the mixture...not too little fuel</TD></TR></TABLE>

Execly, not enough air, which means running rich is when ur getting more fuel which causes it it to backfire

 

it's just one pop tho

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DAguyLS &raquo;</TD></TR><TR><TD CLASS="quote">

Did you ever reset your ecu after those installs?

</TD></TR></TABLE>

 

i do..basically everytime i put something new in i reset it

 

no i didnt, dont know what that is exactly (sorry im kinda new at this) how do you do that?

 

1997GS-R stop making **** up. You're making no sense. Lean conditions cause backfires. This is why: a lean burn is a hotter burn because it is lean. The more fuel there is in a mix, the cooler the charge. The fuel itself helps disipate the heat. In addition to the lean burn being hotter it also burns longer due to the low fuel density in the air charge. This longer burn sticks around for the next intake stroke, where there is nice new (albeit lean) mix to burn, thus the backfire. A rich condition on its own does not promote backfires.

And what you're hearing could just be a break in the exhaust pressure between shifts. It's hard to know if it is in fact a backfire by hearing a description of the noise.


Modified by kchungb17a at 2:13 PM 9/29/2005

 

it does backfire at mid rpm in 2nd

so...set my fpr to rich it a bit?

 

When it backfires, you'll here a pop coming out the intake. Do you here that? Is it pinging? Do you have a CEL on? I'm just having trouble believing your engine is actually backfiring. Arbitrarily increasing your fuel pressure may not be the answer. It will be safer for the engine to run rich, but you're kinda shooting blind. Ever think about getting a dyno run with a wide band O2 read?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kchungb17a &raquo;</TD></TR><TR><TD CLASS="quote">When it backfires, you'll here a pop coming out the intake. Do you here that? Is it pinging? Do you have a CEL on? I'm just having trouble believing your engine is actually backfiring. Arbitrarily increasing your fuel pressure may not be the answer. It will be safer for the engine to run rich, but you're kinda shooting blind. Ever think about getting a dyno run with a wide band O2 read?</TD></TR></TABLE>

with my exhaust it's hard to hear the intake lol i riched it back a bit..50psi...i lowered it earlier today and it was popping in every gear change. no CEL no ping. no money right now to run a dyno...

 

Got it. I feel your pain. Wel if you richen it up and the pop goes away, I guess we can assume that you were backfiring. Too rich though and you run the risk of melting the cat.