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odd boy
May 22nd, 2008, 09:28 AM
Hi,

I've got a question,

Will inceasing the values in VE table lead to riching ing or leaning the car? And how, if possible?

SSpdDmon
May 22nd, 2008, 11:05 AM
Below the MAF threshold (B0120), the PCM determines cylinder airmass based on the MAF and the VE. So, yes, your fueling is effected by the VE. There is pleanty of info and "how it works" kind of documents over in the PCM section on LS1Tech. Best thing you can do is set aside a few hours and start reading. :)

joecar
May 22nd, 2008, 12:42 PM
If the MAF is disabled:
PCM uses B0101 to calculate cylinder airmass (using MAP, IAT, and other variables);
PCM looks up B3605 or B3618 (have you yet figured out which/when...?) to get the commanded AFR;
PCM uses those 2 to calculate fuelmass required;
so, if B0101 is increased and B3605/B3618 are unchanged, the fuelmass will be greater, and measured AFR will be richer.


If the MAF is enabled:
above B0120: the PCM calculates cylinder airmass from the MAF;
below B0120:
- PCM uses both B0101 and B5001 as Jeff said above...
- on transitions the PCM tends to use B0101,
- at steady state the PCM tends to use B5001.
PCM then computes the fuelmass from the airmass and commanded AFR.
so if B0101 is increased, then below B0120 fuelmass during transitions will be greater, but it will remain unchanged during steady state and above B0120.


This is a simplified description... keep reading and asking questions... all the above information is easily found by reading a few forums... LS1tech has a lot of info regarding this.

:)

odd boy
May 22nd, 2008, 04:54 PM
so, if B0101 is increased and B3605/B3618 are unchanged, the fuelmass will be greater, and measured AFR will be richer.

so if B0101 is increased, then below B0120 fuelmass during transitions will be greater, but it will remain unchanged during steady state and above B0120.



I was looking for that answer, thanks both.