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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Hoov41 on October 21, 2014, 09:11:31 am

Title: Can't get rid of backfiring.
Post by: Hoov41 on October 21, 2014, 09:11:31 am

I have had the carb tuned. New cap rotor plugs and wires and everytime i downshift it sounds like a machine gun firing. It's so loud. My exhaust is pretty rusted and has quite a few holes in it. Could that be the issue?

83 K10
4SPD
Stock Gearing.

Title: Re: Can't get rid of backfiring.
Post by: Irish_Alley on October 21, 2014, 04:33:46 pm

Holes can and will pop.

Title: Re: Can't get rid of backfiring.
Post by: 78BIG-TEN on October 21, 2014, 04:40:04 pm

downshift accelerating or decelarating

Title: Re: Can't get rid of backfiring.
Post by: Dan75k20 on October 21, 2014, 08:01:43 pm

(http://tapatalk.imageshack.com/v2/14/10/21/6bf0ea4142697ba146bcd88bcb5da1c7.jpg) lol my header fell apart last week sounded horible and back fired on deceleration the tube was broke going into the collector for a while

Title: Re: Can't get rid of backfiring.
Post by: Irish_Alley on October 21, 2014, 08:56:28 pm

I have a 1/2" hole on my impala on the resonator . it will also pop when I downshift

Title: Re: Can't get rid of backfiring.
Post by: roundhouse on October 22, 2014, 08:22:57 am

Yep.  Holes letting Fresh air into the exhaust will cause popping when your slowing down

My bronco does that.   I kinda like it

Title: Re: Can't get rid of backfiring.
Post by: 78BIG-TEN on October 22, 2014, 08:45:59 am

Looks like its time for some new headers

Title: Re: Can't get rid of backfiring.
Post by: Hoov41 on October 22, 2014, 12:03:47 pm

Thanks. Yeah it's on deceleration. Normally only at higher RPMs I will fix the exhaust hopefully that will work.

Title: Re: Can't get rid of backfiring.
Post by: Dan75k20 on October 28, 2014, 04:07:39 pm

Big ten i had an extra set in my basement