More silly ideas

[Bruce Plecan]

| Bruce Plecan wrote:
| > What if someone wanted to use a straight full time baro correction (for
a
| > MAP system)?.   Could it be done as simply as using a 1bar MAP
referenced to
| > atmosphere, and then the output from that one used as the reference
voltage
| > to a second MAP that is referenced to the engine vacuum.
| >    Then carrying this further how about as a correction for 2+3 bar
MAPs?.
| > All of the above would be require deleting the baro calc from the prom,
and
| > recalibrating the Tables, that are VE related.

| I'm not sure quite what you are trying to do.  I assume you want to get
| rid of the inferred BAP calculation and to substitute a real BAP sensor.
|  A MAP sensor measuring open air, hooked to another ECM analog input,
| and with some code changes would work.

Well, yes, however that is beyond my capabilities.

| If that's not what you want, keep in mind that the ECM computes and uses
| various pressure values.  It has absolute pressure, baro pressure, and
| gauge pressure (aka manifold vaccuum).  For example, one ECM has an
| intake VE table indexed by MAP, and an exhaust VE (aka backpressure)
| table indexed by BAP.  The same ECM also has lots of tables indexed by
vacuum.

That ecm is way out of my league to understand.
What I have noticed there isn't much correction for IAT, and even some baros
that run a fixed value.
   I just want to come up with a simple modification to allow for a constant
Baro correction.
Bruce

| Ludis Langens                               ludis (at) cruzers (dot) com
| Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/