I'm not going to argue with you, but for me your "facts" don't make sense. A solenoid is an on-off device that is either on or off. I'd venture that it cannot modulate to "control fuel air mixture". A PROM chip is simply Programmable Read Only Memory - it's burned with a program, and once burned cannot be changed. Not at all sure what you mean by "...it functions largely on closed loop reference to the 02 sensor", or how it "...sets the run mode to full rich". Your words seem to apply a lot more to an EFI system than a carb, which is a mechanical device using venturis, orifices (jets), and stepped metering rods to transition from idle to mid range to wide open throttle to provide both economy and performance across the operating RPM range.

Good luck sorting out the Chevette. I won't bother you again.