[PheOniX]

Still new to ATR. First time callibrating my MAF. Did a couple runs today so I could do my maf calibration on ATR. Looked like this:

Voltage LTFT
1.24-1.38 -3.28 neutral
1.52-2.02 2.96
2.03-2.33 1.4
2.34-3.07 -3.28
3.08-3.34 -.16


Did some more this afternoon to find that two of my LTFT levels were different:

Voltage LTFT
1.25-1.56 -5.62 neutral
1.56-2.02 4.52
The others were the same

Why would this change?
Perhaps they constantly fluctuate?
What should I use for my multiplier?
Is the ECU still learning?

I have 3 tanks of gas on the flash already but I've probably hit 6th gear only about twice as I sort of live in a bubble at the end of Long Island for my job.

 

[FORZDA 1]

You must post the actual log(s) taken during the MAF cal procedure for anyone to assess your cal.

The LTFT will vary somewhat as the intake air conditions and pressures fluctuate. Do the MAF cal procedure on a flat road at the most prevailing temp, and keep the throttle changes smooth so the ECU doesn't hit the accel enrichment which will affect the trims in the short term.

 

[dougefresh_]

Did some more this afternoon to find that two of my LTFT levels were different...

Why would this change?
Perhaps they constantly fluctuate?
What should I use for my multiplier?
Is the ECU still learning?.

I mentioned this in the "how to maf cal" and what to do about it. They should not "contstantly fluctuate" but they will fluctuate with temp/weather changes for sure. The ECU should be done learning IF you spent enough time in each different voltage breakpoint. That's what Forzda was talking about in another thread.... it's not the 50 miles break in that matters, it's more spending enough time in each breakpoint for the ECU to learn the trims. That's what I do as well, and I just use "Maf g/s and Maf volts" on my DH and try to vary the the volts throughout the range.

As for your multiplier, this is what I do: Do a couple more MAF g/s tests, and make then jot down the multipliers in each break point like you did. Then just look at all 4, and although there may be some 'cross-over' still, there should be one value that it is closer two. Your current breakpoints only diverge by like 2% or so, so it is NOT a big deal. If you have the same problem with a couple more logs, just split the difference. That is, if had
1.52-2.02 at +2.96 and another at 1.56- 2.02 at +4.52, I'd probably just mult that range by 3.75 or something. Ditto for the breakpoints... sometimes you'll see those vary a few voltage points.... just try to eliminate the cross-over with a couple more MAF g/s tests, and just use whatever is closest.

 

[bova80]

make sure to take in account the stft. so if you do a log and your ltft are 4 and your stft are -1 then you'll multiply by 1.03. don't worry about trying to get your trims to 0 cause it won't happen and if it does they won't stay there long. being with in +/-8 is what cobb recommends although I like being around +/-4. and as douge says, it is going to take more than 50miles for the trims to start balancing out, especially in the fall with fluctuating temperatures.