I have a Quest 99 and is experiencing a rough idle when starting engine cold (60º);
I have clean:
– Clean Speed Sensor
– Remove and clean idle control valve (spray with throttle body cleaner)
– Clean Throttle body inside wipping with cleaner.
The IACV in the morning idle is at the left position and after the car warm up (run good not roughness whatsoever) it moves to the left position.
Also have change, distributor cap + rotor, put NGK spark plugs prior to developing this rough idle.