Fuel trim Data logs (help)
06-08-2005, 07:58 PM
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Fuel trim Data logs (help) ok here is the problem, my car 01 Z28 with stock exhaust cept for a flowmaster, have all free mods, bump stop FRA etc, HPP3, MTI lid, powershot filter SLP bellow,160 stat Taylor wires, ported stock MAF
buddies car 01 SS with SLP LT's Hooker cat back, BBK TB, descreened MAF, (had GMS MAF I just removed it tonigh even though the flow #'s were virtually identical), 160 stat, HPP3, free mods, whisper lid, K&N
my car dynoed 325RWHP and 341RWTQ and his car dynoed 340RWHP and 352RWTQ
we are tryign to figure out why.
I took some data logs tonight and it seems his problem is in his fuel trim. here is the data
01 Z28
RPM 838 STFT B1 -4%
MAF 12.53g/s STFT B2 0%
LOAD 4% LTFT B1 16%
TPS .80 LTFT B2 10%
RPM 5094 STFT B1 0%
MAF 231.66 g/s STFT B2 0%
LOAD 82% LTFT B1 16%
TPS 4.53 LTFT B2 12%
RPM 4805 STFT B1 0%
MAF 160.25 g/s STFT B2 0%
LOAD 69% LTFT B1 16%
TPS 4.55 LTFT B2 12%
01 SS
RPM 844 STFT B1 -4%
MAF 15.57 g/s STFT B2 -7%
LOAD 5% LTFT B1 -3%
TPS .55 LTFT B2 -1%
RPM 5138 STFT B1 0%
MAF 247.11 g/s STFT B2 0%
LOAD 83% LTFT B1 0%
TPS 100% LTFT B2 1%
RPM 4537 STFT B1 0%
MAF 22.57 g/s STFT B2 0%
LOAD 31% LTFT 0%
TPS 100% LTFT 1%
the low % and negative FT numbers on the SS, does that mean that the computer is not adding fuel as required by engine load?
buddies car 01 SS with SLP LT's Hooker cat back, BBK TB, descreened MAF, (had GMS MAF I just removed it tonigh even though the flow #'s were virtually identical), 160 stat, HPP3, free mods, whisper lid, K&N
my car dynoed 325RWHP and 341RWTQ and his car dynoed 340RWHP and 352RWTQ
we are tryign to figure out why.
I took some data logs tonight and it seems his problem is in his fuel trim. here is the data
01 Z28
RPM 838 STFT B1 -4%
MAF 12.53g/s STFT B2 0%
LOAD 4% LTFT B1 16%
TPS .80 LTFT B2 10%
RPM 5094 STFT B1 0%
MAF 231.66 g/s STFT B2 0%
LOAD 82% LTFT B1 16%
TPS 4.53 LTFT B2 12%
RPM 4805 STFT B1 0%
MAF 160.25 g/s STFT B2 0%
LOAD 69% LTFT B1 16%
TPS 4.55 LTFT B2 12%
01 SS
RPM 844 STFT B1 -4%
MAF 15.57 g/s STFT B2 -7%
LOAD 5% LTFT B1 -3%
TPS .55 LTFT B2 -1%
RPM 5138 STFT B1 0%
MAF 247.11 g/s STFT B2 0%
LOAD 83% LTFT B1 0%
TPS 100% LTFT B2 1%
RPM 4537 STFT B1 0%
MAF 22.57 g/s STFT B2 0%
LOAD 31% LTFT 0%
TPS 100% LTFT 1%
the low % and negative FT numbers on the SS, does that mean that the computer is not adding fuel as required by engine load?
Last edited by 89ws6formula50; 06-08-2005 at 08:06 PM.
06-09-2005, 11:00 AM
#2
the last 2 of the 3 readings on the SS are at 100% TPS (aka WOT). You are in the power enrichment cycle at that point. PE adds fuel.
The first reading on the SS is less than 1% TPS which probably means you were coasting in gear at near idle speed. The negative numbers mean fuel is being pulled and amounts are not unreasonable.
The Z28 is adding a lot of fuel. That car may need its VE table cleaned up.
The first reading on the SS is less than 1% TPS which probably means you were coasting in gear at near idle speed. The negative numbers mean fuel is being pulled and amounts are not unreasonable.
The Z28 is adding a lot of fuel. That car may need its VE table cleaned up.
