I think my plan after the car is on the road and I am positive the ECU is properly serviced I will throw the car on an old AirCare dyno to see that it says, then do the nutter bypass and try again. I am starting to now get curious exactly which way the emissions, performance and economy goes. According to the official documentation the ECU/ECM/CEC (I'm running out of things to call it but for all purposes I am referring to the emissions computer) keeps the air/fuel ratio at 14.7:1 with a physical either/or adjustment for high-altitude driving but no fine tuning outside of using a wideband O2 sensor and adjusting components not monitored by the computer, else it just tries to compensate for the changes.
My goal today was to inspect and test the stepper motor. It's held onto the BBD with four torx screws. The only warning is that while the pins are loosely retained by a plastic disc on the motor assembly there is a spring that can fall out and easily get lost. If it is not on the center pin in the photo below, make sure it's still hanging out of its recess in the carb body.
When the key is in and turned on the ECU will initialize the stepper motor by advancing the pins out to a full-closed position and then pulling them back. That is what happened on my unit so it's safe to say the ECU, the stepper motor wiring and the stepper motor are functioning. The motor is made up of two windings with taps at each end and in the middle. Refer to the wiring diagram on the last page. End-to-end resistance should be around 140-150 ohms with each half of a winding being half of the total value and no continuity to the exterior casting. The readings should be identical when comparing one winding to the other. It all tests good.
