Well on my 1.6 there isn't an idle control valve, its a electronic switch that kinda hooks onto the throttle body. The problem with mine is that if you rev it high then let off of the throttle and have it into neutral the car will stall sometimes, while other times it doesn't. The car is from 91, so I'd imaging that it's a bad electrical connection or something like that.
PS just checked a manual, and Nissan calls it an Auxiliary Air Control