If the A/C is switched off the idle up valve should be closed if it is working properly. (which you could check)
My Gen 2 NA normally runs and idles fine, but if I disconnect the hose going to the intake manifold (post throttle) the motor will race, because it is the same as opening the throttle.
The other hose is pre throttle so it probably won't affect much if it is disconnected except let unfiltered air into the intake hose and ISC.
You have not indicated how well (or otherwise) the motor was running with the hoses disconnected.