pantera_efi

iTrader: (1)

Hi 2xLS1, I measure crankshaft acceleration, done correctly for OVER THIRTY YEARS. (60-2)
I measure firing/exhaust Phase WITHOUT a CAS with my ECU-882C. (60-2, 36-1, ect).

YOU STATE OPPOSITE TECH "not able to start fast without the CMP" AND THEN STATE "the PCM can determine TDC for all cylinders by acceleration measurement".

So I ASK, how would the PCM KNOW which one of the FOUR cylinders per revolution to allow the spark at 0-90-180-270 ?

Thanks Doza for choosing my 60-2 TW, the Spark Accuracy is 1/4 degree vs the 24xe of 2 degrees.

Lance

2xLS1

iTrader: (25)

I didn't come up with that text explanation. That is a copy/paste from GM diagnostic literature. Perhaps you should be asking GM engineering how it does it.