muffler backfire - Team Camaro Tech
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post #1 of 9 (permalink) Old Jun 9th, 09, 05:31 PM Thread Starter
 
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muffler backfire

What would cause a backfire in my muffler at idle ( a soft pop pop) and on decelerating. I have an MSD ignition and headers. I never noticed it until the headers were installed. I thought maybe a small exhaust leak.
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post #2 of 9 (permalink) Old Jun 9th, 09, 06:35 PM
Mike
 
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Re: muffler backfire

My guess would be the exhaust leak also, since it started happening when the headers were installed
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post #3 of 9 (permalink) Old Jun 9th, 09, 06:42 PM
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Ron
 
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Re: muffler backfire

It never fails!....Everytime I get that annoying putt-putting in my muffles I know that some spark plugs are petering out!.....They are starting to foul due to a weak spark!.....If it's not due to an exhaust leak then install a fresh set of spark plugs!
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post #4 of 9 (permalink) Old Jun 9th, 09, 07:18 PM Thread Starter
 
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Re: muffler backfire

Thanks guys. I'll check those out.
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post #5 of 9 (permalink) Old Jun 9th, 09, 07:20 PM
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Steiner
 
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Re: muffler backfire

It could be a few things. Too lean of an idle circuit can cause decel popping from opening up your exhaust without compensating on the fuel side. Unburned fuel igniting in the exhaust can cause backfires through the exhaust. However, if you are hearing something at idle than it is most likely air being pulled in from an exhaust leak.

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post #6 of 9 (permalink) Old Jun 9th, 09, 10:46 PM
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Re: muffler backfire

Quote:
at idle ( a soft pop pop) and on decelerating.
Classic symtom of too lean...be it seconary butterfly setting, inlet manifold/carb leak, or jetting.....not good for the engine

My Spelling is not incorrect...it is creative

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post #7 of 9 (permalink) Old Jun 13th, 09, 04:30 AM
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Re: muffler backfire

Hole in a Collector or bad Collector Gaskets can blow the Mufflers right off the car when you let off on the gas - particularly if your running a Vacuum Advance Dizzy. The vacuum created in the exhaust system inhales Fresh Air that super heats and ignites unburnt fuel - KA-BOOM! - LOL

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post #8 of 9 (permalink) Old Jun 13th, 09, 11:12 AM
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Re: muffler backfire

Quote:
Originally Posted by Z15CAM View Post
Hole in a Collector or bad Collector Gaskets can blow the Mufflers right off the car when you let off on the gas - particularly if your running a Vacuum Advance Dizzy. The vacuum created in the exhaust system inhales Fresh Air that super heats and ignites unburnt fuel - KA-BOOM! - LOL
.....then you good bye to them as you leave them laying on the pavement behind your car .

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post #9 of 9 (permalink) Old Jul 8th, 09, 08:35 AM
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Re: muffler backfire

I had an staock 84 z28 with a problem with the carb running rich. One day I was driving on the interstate and suddenly I heard/felt a explosion that shook my innards. The car immediatly lost all power and I drifted to the side of the road. Looking underneath the car the muffler had turned itself inside-out in the explosion. Thankfully it burst away from the gas tank. The resulting loss of power was somehow my fuseable link that runs power for the car had somehow burned out in the process.. ??? still dont know how that occured..

Mark
Long Gone: 1984 Z28, 1989 RS
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