MAF History

[Ward]

     GM MAF sensors for 5L engines came out in 1985 for the F car (vette0,
it was Bosch FM type, so called because the air flow was represented by a
frequency, much like Form MAP sensors. The frequency as in the 50 Hz
region.

MY86 F & Y cars used a newer version that was a variable voltage similar to
the MAP sensor.  Both of these sensors were toped out at 250 grams/second
electrically, so don't over think how to get more air trough it, the
computer will never know the difference.

250 g/sec is about 280 HP using reasonable BSAC, (Brake Specific Air
Consumption)

Buick's used a smaller Bosch built MAF that was an FM type, I assume with a
lower air flow measuring capability.

The MAF went away in 1990 due to the very poor durability record, virtualy
no V8 made through it 100k life w/o a new MAF. 

The came new hot film tech. Much beter reliablilty. Ater a couple of years
.... The MY 92 - 95 LT1's were equipped with a much superior Delco modular
MAF that has a higher measurement range.  This back to a FM type.

The Current L29 (454) big block truck also uses a MAF and a MAP, The scan
tool reports air flow in the 300's for WOT, so it has a higher range.

The current crop of OBD II GM V8's use both MAP an MAF, (I think all the
same P/N) to meet the tech requirements of OBD II, one of which is measuring
and displaying peak power. The MAF is used for this and primarily for fuel
calculations, The MAP is back up and used for spark Calculations as well as
several threshold calculations.

If I wanted to use a MAF I would use the newer PCM that is used in MY94 - 95
F and Y cars, Its an under hood design, making wiring a lot simpler, It's a
flash device eliminating EPROM's. Its re programmed via the ALDL connector
at 8192 baud. Has the ability to handle any kind of transmission and
excellent diagnostics.  Sort of like using your old AT to your P2 PC. 

Ward










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