Couple questions about LTFT's???
10-30-2004, 07:58 PM
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Couple questions about LTFT's??? During tuning, after what changes do you have to reset the LTFT's?
How do you reset them?
If I'm just making changes to the PE and Open Loop FA tables do I need to reset them before I data log after making the changes?
Thanks.
How do you reset them?
If I'm just making changes to the PE and Open Loop FA tables do I need to reset them before I data log after making the changes?
Thanks.
10-30-2004, 08:36 PM
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LTFTs will reset on PCM power loss. They do not reset
on programming (unless you do it on purpose with a tool
that lets you).
If you are -only- changing the open loop fueling then
the LTFTs should be stable, and that "environment" you
would expect to remain in play. Hopefully you aren't
trying to tune WOT against a variable positive LTFT
"background".
on programming (unless you do it on purpose with a tool
that lets you).
If you are -only- changing the open loop fueling then
the LTFTs should be stable, and that "environment" you
would expect to remain in play. Hopefully you aren't
trying to tune WOT against a variable positive LTFT
"background".
10-30-2004, 09:08 PM
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Originally Posted by jimmyblue
Hopefully you aren't
trying to tune WOT against a variable positive LTFT
"background".
trying to tune WOT against a variable positive LTFT
"background".
10-30-2004, 09:22 PM
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If your setup is so lean that you require positive
trimming, the PCM will carry those positive trims
into WOT to protect the motor. Since every FTC
can have a different trim and the PCM uses the
last cell it was in, adding that percentage to the
WOT mix, that will kick around the mixture at
random.
Which is why you want low negatives, because then
you are "close enough" to true but just enough rich
that you never see a positive adder applied to WOT.
Negatives, just give you zero WOT meddling.
trimming, the PCM will carry those positive trims
into WOT to protect the motor. Since every FTC
can have a different trim and the PCM uses the
last cell it was in, adding that percentage to the
WOT mix, that will kick around the mixture at
random.
Which is why you want low negatives, because then
you are "close enough" to true but just enough rich
that you never see a positive adder applied to WOT.
Negatives, just give you zero WOT meddling.