Some thoughts and questions on EFI

[DIRK BROER]

Before we decide on what computer to use etc shouldn't we decide what the 
operating enviroment or rather the requirements are?

Ouput would be a PWM signal to the injectors.  You could vary the start 
time and the end time of each injector to get sequential port injection.

For input I suspect we'd need:
O2 sensor - what better way to set the car for part throttle cruise.
Throttle Position sensor 
temperature sensor
RPM sensor - maybe an engine position sensor - so you know exactly which 
cylinder needs fuel / spark next (distributer mounted of course).
and then either a MAP or MAF sensor.
maybe Humidity sensor? - or altimeter?

Is that all?

If that is all perhaps we could also get an idea on what kinda of data 
rates are needed.

02 sensors react relatively slow - maybe 10 readings a sec?
TPS - sensors - at least 10 readings a second if not more
Temp sensors - 1 reading a second
RPM sensor - at 10,000rpm (why not?) - that 600,000 degrees per second.  4 
bumps on the crank shaft (ie - crank triggered ignition) would mean less 
than 1000 per second...
MAP or MAF sensor - 1 per second - maybe  more... 10?

The system would have to work at:
Startup
Idle
part throotle cruise
WOT
anything else?


Next post  what would the algorithm be like?

Dirk