VS M4.4 tuning dead? Start again here?

[DonJon]

Hey,

i know it is a rather old post, but i do have a Problem with the Adjustments in Tuner Pro. I downloaded all the needed Files (Rev_5) and Tried to adjust the Voltage Correction Table, but they won't Change to the Parameters Listed on M4.4 Wiki, but only on Green Injectors. Does someone have an Idea to why this happens?

[Chuck W]

I'm not understanding what you're asking.

What exactly are you trying to change?

[Boxman]

Does anyone know how *exactly* air mass is calculated inside the ECU based on the voltage from the MAF sensor?

I've just had a datalog where momentarily the MAF value pegged to 8191.88 (aka the maximum of the 16 bit number it can be), which resulted in a load-request of >10ms at idle with a subsequent 40ms then 79ms injector pulsewidth and an instantly stalled engine.

Interestingly, the MAF table only goes to 1600, and I double-doublechecked both lower and upper banks in the BIN whether there was a mistake in the MAF table, but there was not. 8191.88 (FFFF) is not in there. It happened several times in the span of several minutes.

So what are possible avenues for the ECU registering 8192kg/hr and acting upon it anyway? Does the input get divided by a reference voltage? I can imagine a short in said reference voltage would cause division by near-zero and hence peg the maximum. Other than that, I'm stumped so far.

[Chuck W]

Any hints in TunerPro? (I'm not at home, so I can 't dig into my stuff).

There may be an equation hidden in there for the MAF values.

[Chuck W]

Where are you seeing/looking at the MAF table? It's not something you can edit in TunerPro, and I'm not finding it in Motronic Suite?

According to what I've found the ECU uses a lookup table to correlate the MAF voltages to airmass. I think it's a multiplier, though.

[Boxman]

Does anyone know how *exactly* air mass is calculated inside the ECU based on the voltage from the MAF sensor?

I've just had a datalog where momentarily the MAF value pegged to 8191.88 (aka the maximum of the 16 bit number it can be), which resulted in a load-request of >10ms at idle with a subsequent 40ms then 79ms injector pulsewidth and an instantly stalled engine.

Interestingly, the MAF table only goes to 1600, and I double-doublechecked both lower and upper banks in the BIN whether there was a mistake in the MAF table, but there was not. 8191.88 (FFFF) is not in there. It happened several times in the span of several minutes.

So what are possible avenues for the ECU registering 8192kg/hr and acting upon it anyway? Does the input get divided by a reference voltage? I can imagine a short in said reference voltage would cause division by near-zero and hence peg the maximum. Other than that, I'm stumped so far.

Reporting back, since in the mean time I figured it out: loose wire in my ostrich cable. The ECU must have grabbed an FFFF value somewhere from in the flashbin due to a bad contact. Squeezing the floppy-cable between ostrich and ECU caused the engine to stall. Mounting a new connector fixed the issue.

Thanks for the suggestions nonetheless, Chuck!

[Chuck W]

Awesome. Glad you found the culprit.

I wasn't finding any reference to the MAF table, other than the note about the look-up table.

[Boxman]

I do have a new question. Anyone here running Piet's RPM+ mod? Some RPM tables were transformed to run on an *40 conversion (max 10200rpm), others stayed on *30 (max 7650rpm).

However, the RPM limiters only go to 7650rpm. I'm wondering how that's supposed to work then. Do the RPM limiters still do anything, or were they just disabled?

[Chuck W]

Sorry. I don't think I ever saw that one. I poked around in the huge (archived) thread, but didn't see anything.

You're into this WAY deeper than I am.

[VolvogoBrrrrt]

If it helps anyone, I have copied as much of the tuning information as I could and put it in this Google drive link. Collin, Chuck, and John have contributed much to this effort and thanks guys!

https://drive.google.com/drive/folders/ ... JZzznsR-eq

You may add your own files, please put them in the uploads folder located here:

https://drive.google.com/drive/folders/ ... xQ6POuM6p-