J-bodies and MAP vs MAF

[Heinrich Gerhardt]

Bruce Plecan wrote:

> -----Original Message-----
> From: Clare Snyder <snyder at huron.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Friday, April 17, 1998 9:22 PM
> Subject: Re: J-bodies and MAP vs MAF
>
> >TBK wrote:
> >> Mass systems had map too. Therefore on the Mass needs to be added. The
> EGR
> >> (digital or linear) may be different. HEI or DIS is slightly different.
>
> >> Subject: J-bodies and MAP vs MAF
>
> .  According to the schematics I've seen, some are MAF and
>  some are MAP based on different years and\or models.  The manuals I have
> only go up to '90, however.
> >> > Does anyone know if any J-bodies are MAP based, and what years or
> models?
> >> >Adam
> >> >
> >There were so many problems with the MASS sensors that GM developed the
> >speed-density prom rather than replace the mass sensors. Many vehicles
> >with the mass installed don't use it at all. Eventually they stopped
> >installing it.
> >--
> You wouldn't happen to have a TSB number on when they were doing this would
> you?.  Or a part no for the wire update/prom part no.
> would you?.
> TIA
> Bruce

  I've seen some J-cars in the junkyard that had a GM decal under the hood
indicating that the EFI system had been converted to speed-density.  It looked
like a TSB sticker.  Don't remember what year had this.
Mr. Goatwrench