Am in the process of updating the Speed Density Log File Analyzer to report MAF data. Admittedly am not MAF detail knowledgeable, so would appreciate some assistance.

$6e, $32B and $32-BUA all have an option to compute BLMs using LV8 or "DISPFLOW". The XDF Flag is: Use LV8 for BLM not DispFlow

None of the above MAF bins show LV8 being selected, meaning "Dispflow" is being used for BLM determination.
DispFLow is not defined anywhere, but the hacks indicate it's Air Flow in gm/sec. All good so far.
But LV8 load, not Air Flow, appears to be used as the controlling factor in many tables, and many Scalars are indicated in LV8 units..

So questions:

• Is it normal that BLM would (always?) be determined from Air Flow rather than LV8?
• Why would LV8 load not be used for BLM?
• All of the above masks have option to use a digital MAF sensor (XDF (0x014 b2): Analog MAF Meter in use (HLM). It appeas that analog is always indicated.
  • Which sensor is normally used (analog or digital)?
  • Does the sensor type make a difference in the data provided and used for tuning?
  • I assume the analog sensor only returns counts/volts and the digital returns a frequency in Hz and also maybe volts. Right?

Any insight appreciated.

 

The '86 - '89 MAFs were all analog type (0 - 5V output). IIRC, '85 was a digital low frequency MAF (34 - 150 Hz?).

The '89 $6E code does not support a digital MAF. The option flag for it was changed to the high gear polarity flag (700R4).

What is interesting about the code for the analog MAF, is that it converts the voltage into digital counts. Then does the look up into the proper MAF table.

RBob.

 

... also pegging up to 1792 pp2 counts like the '7148? That's interesting.

Very underrated ECM code for boost, who'd of thought.

- Rob

 

Thanks RBob!. Interesting about '89 '$6E.

Any chance you or someone else could expand on the other questions not yet addressed.Thanks in advance!

Elky