Well, I can attest to the Electronic motor in the throttle body getting damaged over time from pre-TB injection; I just had to rebuild, (Clean), my TB actuator motor today as it seized on me last night. ECU threw P2112 and P2111 codes, (throttle stuck closed/open).
After removing the TB and Opening up the Actuator motor assembly, I found that the rotor and stator, (the outer magnet shell), were severely corroded. I had to clean it out with a combo of WD-40 and liqui-molly intake sensor cleaner with some assistance from a nylon and a brass bristle brush. I also used some alky electronic cleaning wipes in between treatments. once clean I found it was still binding in the brass bearing that is pressed into the bottom of the motor housing, (the nipple that sticks out the motor assembly). I had to leave some WD-40 in that brass Bearing to get it to operate cleanly. Once reassembled, wind the return spring with needle nose pliers in the counter-clockwise direction until the blade returns to the closed position with authority, (eric cartmen).
Delete error codes with you Favorite code reader to remove pesky check engine light and its off to the thunder-dome, (Autobahn)...