Project update

[Bohdan.L.Bodnar at att.com]

Try the following:

ELECTRONIC CONTROLS AND SENSORS, proceedings of the SAE International
Congress and Exposition (1992:  Detroit, MI).  ISBN 1-56091-215-4.  This
book is 120 pages long.  Unfortunately, I do not have it (yet) as it is
in an ATT library in NJ whereas I'm in IL!  If you choose to purchase it,
the ISBN and title should be sufficient for a bookstore to track it down.  I
recall this book has some articles on nifty research done in universities in
Europe on adaptive controls and some stuff on a truly exotic oxygen sensor
which allows more than bang-bang control of the a/f mixture.

I'm not convinced that cold start enrichment is so difficult to achieve in an
EFI engine.  A *lot* of multipoint injected engines in the 1980s (and earlier)
used nothing more than a cold start injector which would fire for a few
seconds when the ignition key was placed in "run."  This injector is
controlled by nothing more than a thermo-time switch -- essentially, an
expensive electrically/coolant heated thermostat.

If you *really* want to model this stuff, you'll need data on flow
characteristics of your injectors, incoming air flow (easy to pull off if you
have a MAF sensor and know the relationship between output voltage or
frequency and air flow), and desired a/f ratio.  The flow characteristics you
can probably obtain empirically via a graduated cylinder, knowing the firing
time of the injector, and knowing the fuel line pressure relative to (air)
pressure seen at the injector's tip.  This way, you can plot fuel delivery vs.
injector on time.  There are, without a doubt, a whole bunch of other things
you'd have to figure out (e.g., a/f mixture vs. engine temperature...).

I think I'll stick to designing computer systems...

Cordially,

Bohdan Bodnar
bohdan.l.bodnar at att.com