Have a 1999 Honda V6. Car has hunting idle between 1 to 2K rpm. I bought a new IAC and tried to replace the IAC but could not remove the 2 screws. I now find that the throttle butterfly is stuck - it only opens a bit.

My question. Would the throttle position sensor prevent the throttle butterfly from opening? What would prevent throttle butterfly from opening fully. This is not a case of a sticky or gummed up TB. It only opens like say 10 percent of the full range

Thanks