Nissan Repair: 91 pathfinder high idles until engine warm, air control valve, throttle body

Question
The 91 pathfinder  idles at 2000 rpm until it reaches running temp. when it is close to running temp it will idle high for 3-5 seconds but drop to 1500 rpm and idle there. once at running temp there is no problem. I replaced coolant sensor and the one beside it

Answer
Arpad,

Sounds like the idle air control valve is sticking and needs to be replaced.  It sticks up on the intake, just behind the throttle body.  Also, it has a connector much like a fuel injector.  When you check this be sure to clean the throttle body before installing the new one since there is plenty of crud that has coated the inside over the years.