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RacerChris
March 28th, 2009, 02:31 PM
Has anyone had to calculate there VE tables into the 130+'s minimum to get a good Air-Fuel reading???
My engine is a 5.3, 10.6:1 compression, decent Comp Cam, heads ported/polished, Gibson shorty headers w/crossover pipe.
I thought that this engine would breathe well but this just seems not right compared to my last LS1 that would top out at 135 VE.

Anyone have any sugestions???

Black02SS
March 28th, 2009, 04:53 PM
I did once.... Found out it had a bad fuel pump.

TAQuickness
March 28th, 2009, 11:48 PM
For naturally aspirated I would be supsicious of any VE values over 115%. You might want to check for exaust leaks or fuel system problems (as Chad suggested)

RacerChris
March 29th, 2009, 05:59 AM
For naturally aspirated I would be supsicious of any VE values over 115%. You might want to check for exaust leaks or fuel system problems (as Chad suggested)

TA your always a great help!
I now its not the fuel system, I have 63 PSI of rail pressure. I will check for exhaust leaks today.
Do you think it could be a intake leak?? My MAP readings are in the 45-50 KPA area and stay fairly steady.
Also, I have my wideband located at the exhaust crossover to monitor both sides of the engine. I would asume this is the best place to mount it.... Am I wrong???
Thanks guys!

RacerChris
March 29th, 2009, 03:09 PM
Well I figured out the problem!!!!
Under DTC Processing Enablers if you disable any of the MAF tables P0101, P0102, P0103, the engine will not run correctly. You can disable them under MIL enablers but not Processing Enablers.
Hope this eventually helps someone out.

Supercharged111
March 29th, 2009, 04:54 PM
Is there a post somewhere that describes exactly what a processing enabler is? The way you word it it sounds to me like disabling the processing enabler would be the right way to do it too, not letting it be a part of the equation, but obviously the PCM doesn't like that.

5.7ute
March 29th, 2009, 05:57 PM
To run in Speed density mode (mafless) the PCM needs to see that the maf has failed. If you turn off the processing enabler this cannot happen, and some other pseudo fuelling mode is used.

Kevin Doe
March 30th, 2009, 04:12 AM
Well I figured out the problem!!!!
Under DTC Processing Enablers if you disable any of the MAF tables P0101, P0102, P0103, the engine will not run correctly. You can disable them under MIL enablers but not Processing Enablers.
Hope this eventually helps someone out.

I hope you found my thread where I had the same problem. It had me stumped for about a week.

LS1_Dragster
March 30th, 2009, 07:26 AM
I think this is exactly what I was going through the other day! Drove me nuts....

Lee

Kevin Doe
March 30th, 2009, 08:16 AM
Another thing to note is that if youre fuel flow table isn't correct, the VE table certainly be offset.