Assuming this is the rotary idle control valve, having the rpms rise after removing the connector is NOT an indication the valve is sticking. The fact the rpms changed indicates the valve was indeed responding to input - no sticking at that moment, anyway.
Whatever your tech did to determine the valve is sticking, though, bear in mind that disconnecting it you have also removed active loop control from the idle circuit. Many other components in the loop could be malfunctioning to cause your problem - sensors, OVP, ECU, etc. My guess is the valve is not high on the list of likely culprits, and in any event it can be easily removed and tested, cleaned, whatever.
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7