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View Full Version : Backfire and popping under acceleration...Im out of talent



koryenger
August 12th, 2016, 08:50 AM
Hey guys just looking for a little help. Pretty sure I am out of tallent...427 LS3 Cam specs attached. The intake has 2 filters, one side is blocked off and the MAF is located within 4-5 inches of the air filter. Horrible hesitation/backfire right off idle while driving. Also does it under free rev conditions. Truck will clean up around 1600 -1800 RPM and accelerate fine. I cant seem to get rid of the low end backfire/popping. I have gone lean and rich in the P.E with no change. B2013 Dynamic Impact airflow, got a little better.... MAF trims are spot on. What am I missing???
[ATTACH=CONFIG]20083
[ATTACH=CONFIG]20084
[ATTACH]20085

joecar
August 14th, 2016, 05:19 PM
Can you post log files.

Where is the MAP sensor...?

joecar
August 14th, 2016, 05:20 PM
Your MAF sensor is on one of the intake runners...?

joecar
August 14th, 2016, 05:26 PM
Your cam has has 23 degrees overlap @.050, it produces quite a lot of reversion, the MAF will see this, especially being so close.

koryenger
August 15th, 2016, 03:50 AM
Hi Joe, thanks for the reply....the MAP sensor is in the stock location just behind the throttle body. Not sure what you mean by the cam having 23? Here are a couple of logs I took this morning...by all means please let me know if you see anything.2009320094

joecar
August 17th, 2016, 03:28 AM
sorry, somehow I didn't finish typing, I edited my post.

joecar
August 17th, 2016, 03:30 AM
What intake manifold is it, can you show me some more pics of where the MAP and MAF are located.