kPa under boost

[Dave Zug]

I still say that I searched the code for references to the location that was
ID'd in the datastream as BARO and the only one I found was the pointer for
the ALDL item. it was never looked at again once it was written to once.
never written to again or read from. I looked in all code, not just active
code.  of coarse this was a 2bar application.. maybe they cheated and insted
of converting for a 2bar sensor, they just skipped it?

there are those on here who can definetly check this in the 89/90 turbo GP
code, on the 7727 ecm and call me an amateur, liar (or  fraud ;-). I looked
for any reference to the initial location that is BARO, that the code shows
MAP transferred to shortly after key-on and checksum.

the reason I spent so much time on that was I had an idea that I could hook
up a pot to the MAP input and falsify my altitude at key-on in order to
tweak the fueling leaner, then switch in the real MAP sensor to run. it
turned out that it was never looked at again - could mean that it is
calculated some other way but then why is baro in the datastream pointing to
the written-once value??
I went into this detail cause I had to learn by using no "cheater" docs,
just a disassembler and wit ;-D

..As for checking at WOT - my expensive direct piped liquid filled boost
guage (in the NA car now) will show WOT vac readings of anywhere from
negative 2# to zero# depending on engine temp, outdoor temp, and RPM. if
computer does baro reading at WOT it would be running with an assumed baro
until granny punched it to try and blow away that little nash rambler next
to her - good coding?  junkyard engines that were driven by little old ladys
are identified by patterns of oil streams down the inside of the block -
there was never really any jerking around going on so the oil followed the
same channels down the block. probably ZERO WOT events on it.

I really should qualify myself... I've been posting fevorishly, I'm no guru,
just a commercial controls programmer (non-ASM even) who tinkered with one
specific cal, tweaked a buick GN to a 12.7 (not hard) and is working on a
383 for the IROC, and likes learning and doin new stuff. no ecm related
commercial interests. This info is not stated as fact, only my view.

I'll lay off the mega-posts for a bit.

----- Original Message -----
From: Bruce Plecan <nacelp at bright.net>
To: <gmecm at efi332.eng.ohio-state.edu>
Sent: Sunday, November 14, 1999 7:32 PM
Subject: Re: kPa under boost


> ----- Original Message -----
> From: TK <terryk at foothill.net>
> Subject: Re: kPa under boost
>
> As I understand it that is a calculation, not a direct reading off of the
> sensor.
> Grumpy
>
> | Don't some of the ECM's grab a baro reading at WOT?
> |
> |
> |
> | > > ecm reads it during key on- no engine run, it uses that as a baro
> | > > correction.
> | >
> |
> |
>
>