Negative numbers in VE Table
Originally Posted by joecar
The VE Table may be being displayed as a percentage of cylinder volume...
But the LTFT is the percentage that that percentage is out by.
i.e. they are percentages of two different things, so you can't just add/subtract the percentages.
Think of it like this...
If LTFT is -4%, then multiply VE table cell by 0.96.
If LTFT is +4%, then multiply VE table cell by 1.04.
But the LTFT is the percentage that that percentage is out by.
i.e. they are percentages of two different things, so you can't just add/subtract the percentages.
Think of it like this...
If LTFT is -4%, then multiply VE table cell by 0.96.
If LTFT is +4%, then multiply VE table cell by 1.04.
Red:
There is a pretty good injector spreadsheet out there. I don't have a copy but a search will locate it quickly. If you are only real rich at low KPA, you might look at some of the proportional fueling threads and see if they help.
As far as WOT goes, the narrowband O2s are pretty unreliable. A wideband is the only way to gain comfort as to the true A/F.
There is a pretty good injector spreadsheet out there. I don't have a copy but a search will locate it quickly. If you are only real rich at low KPA, you might look at some of the proportional fueling threads and see if they help.
As far as WOT goes, the narrowband O2s are pretty unreliable. A wideband is the only way to gain comfort as to the true A/F.
Thread Starter
TECH Resident
Joined: Aug 2003
Posts: 970
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From: England UK
Originally Posted by Phil99vette
We 0 out the MAF output table and the primary VE Table on 98-00.
Phil
Phil
With the MAF zeroed out and I'm scanning I only get one line in the Advance Table, and in the Retard table, I guess these tables need the MAF to report in the scanner properly?
My STFT's are pretty much zero, so going to use the LTFT values to modify the VE table, adjusting in percentages ie -4% = x 0.96
are my fuel trims OK SD was on, then when logging with MAF, LTFT's were all whacked. Anyway I did some corrections and my LTFT's are now between 0 and -5. Is this a good range or should I tighten it up more. It seems as though it is my idle that is causing it to go down to -5 because while idling my STFT's drop way down from -5 to -9.
