My car backfires when I let off the throttle. It usually occurs after the car slows down and I can make it stop just by putting my foot back on the throttle lightly. Would a leaking injector make this do this or do I need to make some adjustments to the decell fuel shut off or spark timing?

 

backfires out the intake....


or is it in the exhaust?

if it sint he exhaust dont worry about it..

 

Exhaust. I don't like it and would like to eliminate or at least make it less.

 

I have the same problem. probably just because of the LT's ORY and GMMG

 

Do you have any exhaust leaks?

 

No exhaust leaks.

 

yeah... not much you can do about that...

other then get more muffler to quiet it down some..

 

Mine is bad but only after i have accelerated wot and then take my foot of the gas immediately. Exhaust leaks can make it worse and headers also make it more pronounced. I think its from having good back pressure.

 

Could also be bad plugs, mine are bad and arch off my headers causing it to spudder an backfire everyonce and awhile. Do you have a missfire?

 

No misfire. Brand new plugs and wires. Have been very careful to check to make sure wires are not up against headers.

 

mine backfires. its 438 fuel injected rear wheel horse power. Its tuned perfectly.
Mine also backfires on deaccel. Just live with it. You cant get rid of it completely. You could get a sally muffler so you cant hear it i guess, but what fun is that? hehe just playin with ya bud!

 

OK, if yours does it also and it has a good tune, I guess I'll just live with it like you say. I just wondered if some tweaking on the fuel or spark down low or any of the decel fuel cutoff settings would help any. I have a 4 inch exhaust going into a 4 inch inlet and outlet Borla muffler, so I guess that amplifies the backfiring. Thanks.

 

If its the pop and crackle on decell out the exhaust, this is normal for an LT1. Slight amounts of unburned fuel make it out of the head then pop on the hot manifolds. This is totally normal.

With a little custom tuning it can be reduced but usually at the expense of performance. You could also get a quieter exhaust or put your catalytic converters back on.

Mine only does it with the cat off, when I put the cat on its gone.

Dont worry about it, its harmless.