Wide Open Throttle LTFT Coming From Nowhere?
09-27-2012, 08:17 AM
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Wide Open Throttle LTFT Coming From Nowhere? I just finished tuning the VE maps and the MAF tables and I set the PE Table to 1.15 accross the board.
The Fuel Trims for WOT start out at zero when I start the car and they are low in most all cells, but when I go to wide open throttle the LTFT's (fuel cell 22) they jump to 7.8 and 4.7, despite the fact that the LTFT's were pretty close to zero before going into WOT.
I thought that the VCM takes the LTFT from the cell it was in immediately before going to WOT and uses those trims if positive. That is not happening in my case. It seems the trims for fuel cell 22 are coming from somewhere else, but I don't know where.
Am I missing something? I reset the LTFT's and the WOT LTFT started out at zero but again climbed to about 4 and I can't figure out where those numbers are coming from.
The Fuel Trims for WOT start out at zero when I start the car and they are low in most all cells, but when I go to wide open throttle the LTFT's (fuel cell 22) they jump to 7.8 and 4.7, despite the fact that the LTFT's were pretty close to zero before going into WOT.
I thought that the VCM takes the LTFT from the cell it was in immediately before going to WOT and uses those trims if positive. That is not happening in my case. It seems the trims for fuel cell 22 are coming from somewhere else, but I don't know where.
Am I missing something? I reset the LTFT's and the WOT LTFT started out at zero but again climbed to about 4 and I can't figure out where those numbers are coming from.
09-27-2012, 11:07 AM
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Probably locked in from whatever trim cell you left closed
loop, from.
You may transition through cells between scan frames,
that you don't see because the data is "decimated"
relative to the PCM's internal frame-rate. Look back
through the record and see if any FTCs do have those
trim values. But the cell in question may be one you
rarely or never sit in, only slide through quickly.
loop, from.
You may transition through cells between scan frames,
that you don't see because the data is "decimated"
relative to the PCM's internal frame-rate. Look back
through the record and see if any FTCs do have those
trim values. But the cell in question may be one you
rarely or never sit in, only slide through quickly.
09-27-2012, 02:22 PM
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Probably locked in from whatever trim cell you left closed
loop, from.
You may transition through cells between scan frames,
that you don't see because the data is "decimated"
relative to the PCM's internal frame-rate. Look back
through the record and see if any FTCs do have those
trim values. But the cell in question may be one you
rarely or never sit in, only slide through quickly.
loop, from.
You may transition through cells between scan frames,
that you don't see because the data is "decimated"
relative to the PCM's internal frame-rate. Look back
through the record and see if any FTCs do have those
trim values. But the cell in question may be one you
rarely or never sit in, only slide through quickly.
Wish there was one place to look for the FTC values instead of having to manually go through a log and see what they are. Thanks again for your response.
