Desired target values for different driving conditions
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From: Sleepy Hollow, NY
Desired target values for different driving conditions Hello,
I am not sure what the desirable long term fuel trim values are
for (manual transmission, 2000 LS1 engine, F-body):
1. car fully warmed up, car at idle for several minutes
(when near stock my car would gradually go to +22...24% from whatever value it was when driving
2. car fully warmed up, light load, light throttle, say 4th gear going 45 mph
3. car fully warmed up, WOT (or in PE mode)
Maybe there is a reference table where the LTFTs are supposed to be versus the fuel cell numbers?
Thanks,
Gert
I am not sure what the desirable long term fuel trim values are
for (manual transmission, 2000 LS1 engine, F-body):
1. car fully warmed up, car at idle for several minutes
(when near stock my car would gradually go to +22...24% from whatever value it was when driving
2. car fully warmed up, light load, light throttle, say 4th gear going 45 mph
3. car fully warmed up, WOT (or in PE mode)
Maybe there is a reference table where the LTFTs are supposed to be versus the fuel cell numbers?
Thanks,
Gert
You always want minimal trimming, which would
mean your "natural" tune is perfect. If you have
error, you want it to be trimming negative but
still as little as you can get.
The trim drift sounds like an O2 sensor heat
problem, like from headers. Or a bad heater
power connection perhaps. But headers is
my first guess.
At WOT you want zero trims, this is why in
the closded loop cells you want small negative
numbers. The PCM will carry forward any
positive trim across the WOT transition as a
safety measure.
mean your "natural" tune is perfect. If you have
error, you want it to be trimming negative but
still as little as you can get.
The trim drift sounds like an O2 sensor heat
problem, like from headers. Or a bad heater
power connection perhaps. But headers is
my first guess.
At WOT you want zero trims, this is why in
the closded loop cells you want small negative
numbers. The PCM will carry forward any
positive trim across the WOT transition as a
safety measure.
