low idle. 94 f150 5.0L

my friend has a 94 f150 5.0l, engine was rebuilt and has about 3000 miles on it. he said this has happened before he had gotten the engine rebuilt also. when he starts it up in the morning(cold days) and it drops to a really low idle and almost dies, it also does it when he gives it gas while it is idleing. he had changed the o2 sensor, im thinking it is one of the air control sensors? what do you guys think?

Fords do have lots of problems with Idle Air control motors.Unbolt it with plugged in and have someone turn the key on and off,engine not running.Should move with the key on and go back with the key off