MAF cal log assistance needed

[bfak66]

I'm attempting my first MAF cal here - Flashed the OTS map appropriate for my mods and then drove about 90 miles. I did a good mix of city and highway driving while trying to get through the rev band in different gears.

I did my first closed loop data log. started logging when I was under 1000rpms and went close to redline making sure i got over 100 grams of airflow. My results are attached. Should I be concerned about how jumpy my mass airflow is? Or does this look like I just didn't do the datalog properly?

[Raider]

Made a new thread to avoid cluttering the how to.

[ms3blackmica]

Brian you performed the log very well.

However it seems the log did not capture any trims for the idle region (i.e. under 5.7 g/s).

You should perform the log again, but this time also come to a stop and idle before you end the log, to see what the LTFT is at idle.

[bfak66]

@ms3blackmica Thanks for the tip yesterday. I actually went back this morning and adjusted the LTFT Learning Zone breakpoints to match yours from the tutorial video. Flashed it this morning and just got back from driving about 70 miles and did a few data logs. Here is one of them.

It looks good I think but is it okay that there was no change in LTFT after 50grams MAF breakpoint? I confirmed that I did make the proper changes to the breakpoints on the map that I flashed my car with this morning.

[ms3blackmica]

Originally Posted by bfak66 @ms3blackmica Thanks for the tip yesterday. I actually went back this morning and adjusted the LTFT Learning Zone breakpoints to match yours from the tutorial video. Flashed it this morning and just got back from driving about 70 miles and did a few data logs. Here is one of them. It looks good I think but is it okay that there was no change in LTFT after 50grams MAF breakpoint? I confirmed that I did make the proper changes to the breakpoints on the map that I flashed my car with this morning.

It is possible that the you did not drive for long enough in that breakpoint to register a LTFT. I know we say 50 miles, but sometimes that is not enough. Sometimes 100 miles is more ideal and yeilds better results. You should log STFT so you can see how the ECU is correcting fueling in relation to the set LTFT. If you see very little correction being made through the STFT during the breakpoint where you see 0 LTFT, then thats a good indicator that no adjustment is needed there.



EDIT: Brian, sorry I just realized what you actually meant. I looked at the log way too fast. You have LTFT values all the way up 80 g/s. That sounds about normal. It tends to be difficult to actually get a learned LTFT up beyond that as your not normally driving in that region. The log looks good. I would work with what you have now.

[bfak66]

Did the first MAF cal, reflashed, and am going to continue driving another ~75 miles. So after my next closed loop log I should be hoping to get LTFTs of less than ¦2¦ right?

[ms3blackmica]

Originally Posted by bfak66 Did the first MAF cal, reflashed, and am going to continue driving another ~75 miles. So after my next closed loop log I should be hoping to get LTFTs of less than ¦2¦ right?

Essentially...

But don't get to picky...your trims are always going to be changing with temperature, fuel quality, etc..etc...

Just get them as close to 0 as you can and be happy

[bfak66]

@ms3blackmica I'm kind of confused by my logs as there is no change in LTFT after hitting the 18gram and 30 gram breakpoints. Is this normal?

[ms3blackmica]

Originally Posted by bfak66 @ms3blackmica I'm kind of confused by my logs as there is no change in LTFT after hitting the 18gram and 30 gram breakpoints. Is this normal?

It doesn't "have" to change through every breakpoint.

You just happen to have a good calibration and the learned LTFT for 18-30 is the same as 5.7-18

Good work.