[Shotimes] BARO sensor

[Ian Fisher]

I don't own the Probst book but this conversation
inspired me to open up my "Understanding and Modifying
Ford Fuel Injection" by Ben Watson and read up on the
BAP and MAP sensors. I don't know how the Probst book
is broken down but Watson's book has excellent
descriptions of each sensor, it's function and how it
works as part of the entire EEC system. Great book!

Of course I learn just as much from reading Adam
Parrot. =)

Oam


--- Kevin & Cheryl Airth <clubairth@peoplepc.com>
wrote:

> Adam:
>  Thanks for the in-depth review and answer!! Learn
> something new everyday in
> SHO Land!
> .
> .
> 
> 
> 
> > >> So the DPFE does NOT tell the PCM what the
> BP/MAP is? But BP is
> calculated
> > or inferred from the other sensors? I had it in my
> head that somehow the
> DPFE
> > fed a BP/MAP reading to the PCM. <<
> >
> > For some reason, I used to be of the same thought
> (that the EEC inferred
> BAP
> > readings from the DPFE sensor or EGR system on the
> Gen 2 ATX cars).  It
> wasn't
> > until I consulted my EEC strategy documentation
> that I discovered that, on
> > non-BAP-equipped cars, the EEC infers it's BARO
> readings from other sensor
> > inputs (usually the MAF, ACT and TPS).
> >
> > >> Now this makes me ask: If the BP can be
> inferred from other sensors,
> why
> > would a cheapskate like Ford spend the money to
> install a separate BP
> sensor?
> > <<
> >
> > While there several theories floating around out
> there, I personally
> believe
> > the answer has to do with the fact that, at the
> time, the Ford engineers
> > relied upon these additional sensor inputs to
> supplement their
> relatively-new
> > mass air flow technology.  As time went on, the
> engineers were able to
> refine
> > the inferred strategy to the point where the
> MAP/BAP sensors were no
> longer
> > needed, resulting in a significant cost savings.
> >
> > >> Also the SHO does NOT have a MAP sensor (and
> this is required) so the
> > inferred method seems to be missing something for
> our SHO's? The equation
> > below does not use a MAP input so maybe the MAP is
> not needed as an input
> at
> > all? <<
> >
> > In studying several of the various EEC strategies,
> I have found that the
> > actual logic and sensor inputs used to infer
> barometric readings will vary
> > depending on the calibration or strategy in
> question.  Some early setups
> (like
> > some '89-'95 Mustangs) required both sensors,
> while others (like the
> '89-'95
> > MTX SHO) relied solely upon a BAP sensor. 
> Eventually, Ford ditched both
> > sensors altogether and looked to other sensor
> inputs to derive the needed
> > atmospheric readings (as noted above).
> >
> > Adam
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