Programming 101

[Bruce Plecan]

This is again specific to the 747 ID number 42.
For educational purposes only.
This is part of a letter between me and someone else comparing notes.
Please read all of 101 before trying to use this info.
I tried to edit this, but it comes out choppy partly in do to the topics
Enjoy

>The one single most important value in this calibration is $02b4.  This is
>your base fuel and air calculation.  It is giving the ratio in this value
for
>the rest of the fuel control.
>In the area of $02d6 is your base injector functions.  These are constants
>that are produced on a flow bench.  The injectors are flowed and some
pretty
>sophisticated equipment is used to determine these #'s.  These #'s are
usually
>available from the part vendor.  (Bosch, etc.)  but that does not mean that
>they will necessarily give them to you.   These values should never be
touched,
>unless you have the data, or you really know what you are doing.  Injector
>bias is the amount of time that it takes for the injector to open.  There
is a
>split second of time that the signal is sent and the injector actually
opens.
>This time increases with fuel pressure and battery voltage.  That is where
the
>values around $03e9 come into play.  It is essentially the time that it
takes
>for the injector pintle to lift off its seat, with less voltage that time
is
>longer.
>This VE table is screwy.  I knew that the values in $03c7 were not WOT
fuel.
>I had changed those values before and it brings the whole fuel curve up or
>down.  This is like a base value that the VE (fuel) table starts from.  It
>then takes the values in $037F divides this # by 2 and adds the value to
the
>other table back @ $03C7.  What that allows is for better fine tuning in
the
>emissions range.  The values @ $03C7 are probably the VE @ a specific MAP
and
>RPM, and use this same MAP point for the entire table.
Bruce