If your 146 has a metal cam cover, the idle control valve is the small black device bolted to the top of the throttle body. This is a very simple rotating vane type valve, but is prone to getting stuck due to carbon deposits. Sometimes giving it a gentle tap will sort it out; if not, then you need to remove and clean it.
If your car has a plastic cam cover, with the ECU mouted on top of the throttle body, the the idle speed is controlled by a stepper motor that acts directly on the throttle butterfly. This device has no adjustment; it is controlled dy the ECU, and can only be reset using a diagnostic machine.
In both cases check basic things like throttle cable (adjusted correctly and not sticking) and possible air leaks.
I strongly advise against cleaning the MAF, as this often causes more problems than it solves.