165 to late MAF

[gabe]

On an '870 ECU for an '85 5.0 TPI, does the piggyback module for the MAF do
anything (other than burnoff) that I cannot do with relays myself (power on and
off the MAF).

I guess what I am trying to ask is:  What, exactly, are the piggyback module's
functions?

I am currently powering the MAF with a Bosch SPDT relay and sending the MAF
signal straight into the ECM, is there anything wrong with doing it this way,
other than I lose the automatic burnoff function?  I do not have the piggyback
module and cannot convert to my '165 ECU due to not having the correct Memcal
located yet.

Gabe

Mike Rolica wrote:

> Only for the early 85-86 models.  Then they went to voltage on 87-1990.  Had
> lots of trouble with the early freq mafs.  That is why BUA has a bit for
> freq or analog.
> Mike Rolica
> Meridian Magnesium Products
> Strathroy, Ont
> Ext. 260
>
>         -----Original Message-----
>         From:   Bruce Plecan [SMTP:nacelp at bright.net]
>         Sent:   Saturday, November 27, 1999 8:35 PM
>         To:     gmecm at efi332.eng.ohio-state.edu
>         Subject:        Re: 165 to late MAF
>
>         Going by what I read in the ecmguy's HAC the 165 MAF is Frequency.
>         Starting at 069A (ref BUA), we have the Ld var for scaling LV8 Scale
>         Factors,
>         and just before that we have MAF frquency 34-150 Hz, sounds like
> frquency to
>         me.
>         Grumpy
>
>         | Waaait a min, how are you getting around that the new GM MAF is
> frequency,
>         | and the old is voltage? Build a translator box for freq to volt?
>         | At least with the Porsche 928 MAF it wouldn't need any
> translation...
>         | Maybe one of the code wizards can rewrite the code so it can use a
> freq
>         MAF?
>         | I'm awaiting this as I want to start modifing my 89 and one of the
> first
>         | things that I want to upgrade is the entire air inlet tract
> (Firebird).
>         | Tom
>         |