Toyota Repair: 2000 Tacoma 2.7 high idle 1200-1400rpm, air intake system, small screws

Question
It does this even after being warm. I pulled the throttle body off and cleaned the inside. And removed the IAC. I tested the OHMs on the RSC pin and B+ pin and got 60 ohms. Tested the B+ and RSO and got 5 ohms. I put 12volts to the B+ and neg to the RSC and the valve only twiches, it moves be goes right back to were it started. Then when I put the power on B+ and neg on the RSO it does nothing at all. The truck had no check engine light and no codes just idled high. The IAC valve is expensive so I dont want to replace it if I dont have to. Also the temp gauge in the truck stays in the cold area. It will bounce up every now and again on long trips but never stays up. I tried shorting the wire that goes to the sensor at the front of the block to ground and checking to see if gauge read hot but it does not move.

Answer
The IAC valve malfunction does not set a trouble code, they tend to stick because of carbon deposits which can be cleaned using some air intake system cleaner and a brush, if that is not an option the valve should ve replaced. If the gauge doesn't move when the wire is grounded then the gauge on the dash is bad or the is a circuit board problem on the back of the instrument cluster, remove the cluster and check to see if all the small screws are tight, look for any burned spots, if not then replacing the gauge would make sense.