1227747 Diacom output?

[jgwynne at mrcday.com]

| Ya, for me the brain dead solution would be to record a 'run' with diacom
| (all the inputs to the 7747, including o2), and just feed them back to the
| benched ecm.  With a little software, it seems that you could 'lean out' the
| o2 sensor for the next run, 'richen it up' for another software simulated
| run, etc.  Hence the simulator.  I figured Diacom is an easy way to record
| this run.

Unless the O2 input back into the ecm is made a function of injector
pulse width, the feedback loop will not be stable. I recall someone
posted having found code in a gm ecm that a PID (proportion integral
differential) controller was used to control mixture and keep the O2
sensor cycling (because of hysteresis). It shouldn't be that hard to
make something simulate the feedback.

john