RevGTO

iTrader: (12)

I've been running OLMAF for a number of months now daily driving and it's working great. Had three trips to the track lately running against my buddy. Typically, our cars (with nearly identical mods) run neck and neck. Last Sunday it was relatively warm and I got the better times. But tonight, like a couple of weeks ago, when it's been cold out, his times improve and mine stay the same.

My car really used to respond to cold air and I've noticed that since I'm OLMAF it hasn't. I've run the wideband and AFR is in range.

Would the lack of O2 feedback prevent my car from responding to conditions and achieving optimum fueling? I thought that this depends on the MAF and the lack of O2's wouldn't affect it. But maybe I'm wrong??

Frost

iTrader: (45)

Car is always in OL at WOT anyway..

RevGTO

iTrader: (12)

But LTFT's are active at WOT. When in OLMAF, there is no fuel trimming.

XpertWS6

iTrader: (2)

in your case you gonna need the o2sensor,the mixture metering depend on the o2 sensor,coolant sensor and the air filter box sensor.so you will loose the advantage in cold weather when you car can mix more fuel to the cold air in the intake and get you the extra horse power you use to get in these condition. see you @ the track.

Frost

iTrader: (45)

Their previous learned value will still be applied if they are not cleared out.

RevGTO

iTrader: (12)

If LTFT's are turned off, and the PCM is reflashed with the OL tune, are the old LTFT values cleared?

Frost

iTrader: (45)

With a write-entire they should be, if it's a quick flash (just data update) then they are not. Either way, it's a 2 second thing when you beginn scanning.

RevGTO

iTrader: (12)

You're talking HPTuner lingo and I speak EFILive, so I'm not sure if we're equivalent, but, a calibration update would not clear that data? I don't recall seeing anything in the scan tool for doing this ... any suggestions on that? I'm out of town and don't have my EFI laptop with me.

Frost

iTrader: (45)

It's in the HPT scanner, so it is likely in the EFIL scanner under PCM/VCM controls.

If you have the options to do two updates; 1 being calibration, and one being a full binary re-write, you want the second option.

RevGTO

iTrader: (12)

Yep, the full rewrite is what you do when you change to a different operating system as opposed to the calibration only reflash. I'll see if I can find the proper command in the scan tool to take care of it. I thought turning LTFT's off would simply put an end to them, so I'm surprised to find out that they can still be affecting my OL AFR table/MAF based fueling. And if that's the case, I hope I don't have to go through weeks of WB monitoring and adjusting my tune to get it close all over again after clearing them.

Regardless, I'm not seeing the cold weather gains I typically do with this tune, so something isn't right.