MAF History

Ken Kelly kenkelly at lucent.com
Sat Mar 27 21:48:21 GMT 1999


Andy,
	Dave Hempstead and I are working on tools for the 94-95 LT1 computer. I have an
editor that will currently handle the basic switches, and the Ignition tables. I
am working on the Fuel tables now. Dave has a scanner running, and is working on
a program to download through the ALDL. Free tools should soon be available.
Expensive ones are available now.

		Ken

andy quaas wrote:
> 
> Have the important tables/switches been identified in these ECMs?  Can i
> make a programmer?
> 
> Andy
> 
> --- Ward <wspoonemore at excite.com> wrote:
> >
> >      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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> > http://mail.excite.com/
> >
> 
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