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Deceleration fuel enrichment

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Old 09-12-2013, 08:42 AM
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Default Deceleration fuel enrichment

I have the usual popping under deceleration in my LS3. The decel fuel enrichment setting is set to OFF (as read by my Tech II). I understand there are things that can be adjusted to reduce the popping, such as adjusting the coast down tables and possibly adding more timing at low rpms.

Does anybody have experience with this?
Old 09-17-2013, 01:06 AM
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The table you're looking for is DFCO.
Here's a link to a HPT discussion on the topic: http://www.hptuners.com/forum/showth...4-What-is-DFCO
Old 09-20-2013, 05:05 PM
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Thanks. I also have high STFTs. Like 30 at idle. I wonder if they're related?
Old 09-20-2013, 05:14 PM
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Originally Posted by CFster
Thanks. I also have high STFTs. Like 30 at idle. I wonder if they're related?
Could very well be.
  • Popping during decel is a result of a lean condition.
  • High fuel trims are a result of a lean condition that the PCM is trying to correct. I.e. adding fuel (+ trim) to reduce AFR.

As fuel trims are disabled during decel, if you're running lean prior to entering decel, it's likely you'll be lean during decel. This could be caused by VE table values or incorrect injector values. It will take some logging and testing to see where the problem lies.

P.S. it could also be a combination of problems.



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