OK guys I tuned the VE table with a wideband to within 2% on almost all cells. I pulled the wideband, reenabled closed loop and now I'm seeing short term fuel trims avg between -1.2 and + 1.2 but my LTFT are 5+ to 17+. What the hell is going on? Should I just ignore or disable LTFT?
BTW: I'm using lean cruise on an 04 GTO and running around 16.4 AFR when in those cells.
2004 Yellow M6
HPT Pro, LM1, SVEDE, 85mm FAST Manifold, 85mm TB, TR224 112 Cam, TEA ported/milled 243 heads, SW LT headers, SW Custom Side Exhaust, King springs, Pedders shocks, Hotchkis sways, Pedders & ES Bushings, DBA rotors, Hawk/Axxis pads, Stoptech lines, shiftlight, AP Sideskirts, AP rear bumper, 05 hood, SAP grilles, Hoens, dual aeroforce gauges
Stock 309.8 RWHP 330.7 RWTQ
Now ? RWHP ? RWTQ
1 of 1014
2017 Audi A5 2.0T Cabriolet (bone stock) Daily/winter driver
your 02's seem really lazy to me. Mine switch much faster. But I have never been able to get my 02's to agree with my wideband. There is always a 2-5% difference between the two. I disabled my LTFT since I know my truck is tuned with the wideband all the way up to redline. I didn't want the LTFT to be adding to PE when I would get on it. If you are tuned within 1-2%, then stft should be just fine.
2003 Chevy Silverado Daily Driver, 408 Iron Block,
LS3 Heads/Intake, 231/239 114, 4L80e, Yank SST 3200.
^ It's odd you say that because I have been very nervous about trims vs my WB corrections lately... Just being paranoid, I guess..... Wondering if my WB is accurate, or setup correctly thru the EGR, but my trims are within 1%, so I guess it's not too far off.
And OP, how often do you re-calibrate your WB? When was the last time your trims were reset?
Last edited by Bayer-Z28; 09-13-2012 at 08:12 PM.
2002 Z06 corvette. Heads cam. The usual.
Trims get reset every time I flash it right? So at least daily since I've been working on the high octane spark table.
I'm not running the wideband right now but I ran it for about a month and it was very consistent. I set the offset in HPT for the wideband to read "perfectly"
2004 Yellow M6
HPT Pro, LM1, SVEDE, 85mm FAST Manifold, 85mm TB, TR224 112 Cam, TEA ported/milled 243 heads, SW LT headers, SW Custom Side Exhaust, King springs, Pedders shocks, Hotchkis sways, Pedders & ES Bushings, DBA rotors, Hawk/Axxis pads, Stoptech lines, shiftlight, AP Sideskirts, AP rear bumper, 05 hood, SAP grilles, Hoens, dual aeroforce gauges
Stock 309.8 RWHP 330.7 RWTQ
Now ? RWHP ? RWTQ
1 of 1014
2017 Audi A5 2.0T Cabriolet (bone stock) Daily/winter driver
The trims don't get reset when you flash it. if you want to reset them, you can go into the scanners vcm controls under the fuel tab and reset. If you are fuel tuning and not resetting the trims after every flash, you are running yourself in a circle.Originally Posted by radkon
2003 Chevy Silverado Daily Driver, 408 Iron Block,
LS3 Heads/Intake, 231/239 114, 4L80e, Yank SST 3200.
Lazy O2 sensors follow from long tubes, and will steer
your fuel trims off to the + side and drive closed loop
low-pedal / idle operation rich.
If you get it clean in open loop tuning and then it goes
to crap when you re-enable closed loop, this is your
problem most likely.
Didn't realize that. I haven't been messing with fueling, just timing.
I am running long tubes so that explains it.
2004 Yellow M6
HPT Pro, LM1, SVEDE, 85mm FAST Manifold, 85mm TB, TR224 112 Cam, TEA ported/milled 243 heads, SW LT headers, SW Custom Side Exhaust, King springs, Pedders shocks, Hotchkis sways, Pedders & ES Bushings, DBA rotors, Hawk/Axxis pads, Stoptech lines, shiftlight, AP Sideskirts, AP rear bumper, 05 hood, SAP grilles, Hoens, dual aeroforce gauges
Stock 309.8 RWHP 330.7 RWTQ
Now ? RWHP ? RWTQ
1 of 1014
2017 Audi A5 2.0T Cabriolet (bone stock) Daily/winter driver
^ That LT O2's thing isn't the first time I've heard that...
2002 Z06 corvette. Heads cam. The usual.
Reply With Quote