popping, backfire durring engine deceleration
popping, backfire durring engine deceleration anyone else know what this is about? its been doing this since i bought it and am just now getting around to fixing it. its running rich and its pulling alot of timing. ALOT. like 13 degrees alot. i think it has something to do with the AIR system but im not sure. iv had the car tuned since i bought it and it didnt change anything. both o2s have been replaced, although 1 of them is a bosch, but im replacing that one with another acdelco next week. i thought it might be the maf but i unplugged it and it ran exactly the same. maybe a little rougher. any help?
this topic has been brought up before, iam guessing since you dont have cats, emissions etc. Do you have a lt4 km? i noticed a big decrease on mine before and after, which decreases the km to read false knock.
TECH Senior Member
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Joined: Oct 2006
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From: Decatur, TN (N-W of Athens)
Depending how high in the RPMs are, and what gear I've forced the trans into, mine does it as well. I don't cal it missing, it's just popping.
So if I'm doing 45-50 mph in second and I let off, there's lots of gurgling and popping.
Might sound bad, but it's healthy as a horse.
So if I'm doing 45-50 mph in second and I let off, there's lots of gurgling and popping.
Might sound bad, but it's healthy as a horse.
TECH Enthusiast
Joined: Sep 2006
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From: Spencerport, NY
If it is running rich then it could be that. If its already tuned then having a free flowing exhaust can be the culpret. It is possible that under full throttle there is much un spent fuel being pumped into the exhaust system and when letting off the throttle this can allow that charge to possible ignite. These cars do pop quite a bit, my friends 96 does it and used to do it much worse. I can't really remember what he did about. But I know he installed larger injectors, rockers, replaced the flomaster with a loud mouth.
Depending how high in the RPMs are, and what gear I've forced the trans into, mine does it as well. I don't cal it missing, it's just popping.
So if I'm doing 45-50 mph in second and I let off, there's lots of gurgling and popping.
Might sound bad, but it's healthy as a horse.
So if I'm doing 45-50 mph in second and I let off, there's lots of gurgling and popping.
Might sound bad, but it's healthy as a horse.
I've noticed that from mostly Trans Ams.. but I have seen/heard a 97 SS do the same thing.
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12 Second Club
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From: North Versailles, PA
If I'm on the gas pretty hard and let off at mid to high rpm I get a pretty loud pop and from what I'm told I shoot some pretty nice flames. It happens. I've never heard of any way to solve this. When was the last time you changed your fuel filter. Sounds dumb but who knows.
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Verdad Gallardo new acdelco fuel filter, new delphi pump, decent amout of decarb ran through it, if you look throught the throttle body it is damn near bare metal in the inside of the intake, i try to keep it as clean as i can.throttle blades are shinny, iv been told that the computer is supposed to shut off fuel when you let off the gas and for some reason its not. maybe fuel pressure regulator? newish ngk tr55s, um. i cant think of anything else right now though.
Launching!
Joined: Aug 2006
Posts: 209
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From: Lewisville, TX
Don't worry about it, all cars do it. my buddy's '91 TPI does, my '04 5.3L does it, my '95 LT1 does it, my old '92 Accord did it as well, especially when it had the test pipe installed. i've heard it in completely stock cars although it is VERY quiet. completely normal, if you want it quieter then get OE style cats and mufflers.
Staging Lane
Joined: Nov 2006
Posts: 70
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You said you had a slight exhaust leak on the right side right? Sometimes when you let off the gas you can pull fresh outside air in the place where the leak is and the heated exhaust will make the incoming air go pop and gurgle. My friend's GTP had a really bad exhaust leak and when he would rev it up and let off the gas it would pop and throw flames out the tail pipes about a foot long!
hmm well i guess ill go fix that leak to start with. but what about the knock retard? 13 degrees? WITH the lt4 km? what was it doing before? i might try and replace the knock sensors. i believe the leak may be causing some of it but its not THAT bad of a leak to cause 13 degrees
On The Tree
Joined: Sep 2005
Posts: 169
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Popping and shooting flames are a result of timing and fuel mixture. If the car runs well otherwise, chances are nothing is wrong. Your condition is a tuning problem. Well, if you don't like the popping it's a problem. Some guys like popping and shooting flames, but others don't (I personally don't like it). Your tuner should be able to adjust it for you.
