The ford IAC's use Pulse Width Modulation (PWM) to vary how far the plunger opens.
If 12 volts fully opens the plunger 6 volts will open it halfway. With PWM of 50% on, 50% off, the solenoid thinks it's getting 6 volts.
The ECM varies the PWM to open/close the IAC, and remembers where it was before as a starting point.
I just want to know if partially open is the starting point........
I get about 1/8" of travel from the starting point to fully open. (or as open as it's going to get).
If that's correct, I'm good. The plunger doesn't seem as sticky as when I started, so I may be fine now............