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Old 08-08-2009, 03:07 PM   #1
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Backfire on Decel
Hello everyone,
Looking for some tips on what and where to start tunning. When the car starts to decel from 50 to 60 mph it back fires and pops and bangs. It does not sound very good. Just wondering if there is a tune tip to point me in the right direction.
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Old 08-08-2009, 05:04 PM   #2
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Re: Backfire on Decel
Could be a lean pop, try to give it more fuel while decel.
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Old 08-09-2009, 02:25 AM   #3
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Re: Backfire on Decel
More fuel in DFCO, thats a new one on me.... Lower the closed throttle SA table, maybe also DFCO spark.
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Old 08-09-2009, 12:33 PM   #4
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Re: Backfire on Decel
Hey thanks the closed throttle SA table seemed to help a lot. Just a little pop on decel now. I am going to try and add a little more fuel. What is DFCO?
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Old 08-09-2009, 01:15 PM   #5
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Re: Backfire on Decel
DFCO- Is Decel fuel cut off = No fuel at all, BPW=0 no tuning to do while DFCO just when it should enables and disables.

Lean pops under Decel is a "balance" between spark and fuel (as always....)
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Old 08-09-2009, 10:04 PM   #6
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Re: Backfire on Decel
I can't seem to find the DFCO spark setting? where is this located? Also what do you mean by BPW=0? If that is set to 0 then I don't need to change any other DFCO settings?
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Old 08-09-2009, 10:49 PM   #7
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Re: Backfire on Decel
Don't rule out exhaust system leaks. That is the typical cause of backfires and bangs from the exhaust on a throttle lift.

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Old 08-10-2009, 04:43 AM   #8
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Re: Backfire on Decel
Quote:
Originally Posted by brandenbtl16 View Post
I can't seem to find the DFCO spark setting? where is this located? Also what do you mean by BPW=0? If that is set to 0 then I don't need to change any other DFCO settings?
I dont know of any DFCO spark setting. The spark advance while decel/dfco is from mail spark table or closed thottle table depending on code.

BPW=0 is Base pulse Width is 0 injectors are not open at all, this is while DFCO is active. You must seperate DFCO and Decel two diffrent things.
Last edited by gta324; 08-10-2009 at 04:48 AM.
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Old 08-10-2009, 04:43 AM
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