Why negative numbers in the MAS Airflow section?

[JoshkerLS1]

My logs look something like:
35.2
36
37.2
38.4
-39.5
40
-42
-43

Any ideas? Or is this just a bug with the software?

[SSBerserker]

Same deal... I am running a turbo on an LQ9 and get negative numbers for MAF at WOT. :huh2:

[Casey]

Can you guys send me your logs so I can look at it.



Thanks,
Ken

[mustbbrent]

Ken, I have the same issue but with a twist. I sent an email to [email protected]... I need to look to see about a response yet... but I can't read the scanned files anymore. What other stuff would you like to see in the logs? And do you want the .hpl or the .csv???

[Casey]

I got your files and am looking over them now.

I can open your old files, so getting this resolved
won't be a problem.


Ken

[mustbbrent]

You guys are awesome. Let me know if you need anything else. And feel free to make recommendations if you see that my tuning needs some help. :P

I got your files and am looking over them now.

I can open your old files, so getting this resolved
won't be a problem.


Ken

[jimmyblue]

Wonder if this is what happens when your MAF sends
a frequency greater than the PCM limit - flipping the
binary representation over to a negative (since the
basis internally seems to be integer two's complement,
this could happen?).

Two questions there - one, how does HPTuners logger
represent the data returned; two, what does the PCM
do with over-the-top data? Perhaps there is some "clip"
math embedded downstream, that saves you from such
sensor / sensor front-end scaling kookiness.

[Chris@HPTuners]

it's not a big problem, we just got the signed/unsigned flag wrong on this one.

[JoshkerLS1]

My appoligies for disapearing from this post, do you still need my log or is the problem figured out? A software bug?

[Keith@HPTuners]

I don't believe the issue will be solved in the 1.4 release which will happen any day now, but it will be fixed very soon.

[JoshkerLS1]

Well thanks I think I might want to point out that this seems to induce knock when this happens, is that possible?

[FastFieros]

I can tell you that on a 97 GTP I scanned, the PCM was done by (lets say other than HPT) and it had - timing and - MAF in the scanner logs. It was noted in another section of this forum that the signs where just wrong in the scanner application for this timing event and MAF event, the numbers were valid and consistant with the others. I scanned 99 and 00 GTP's with no problems on the logs.

Loyde