Ok now i have replaced the engine coolant sensors, the two sensors i need to replace are the idle speed motor (idle surges) and the sensor right next to it. I have no idea what that one is but if it's unplugged the truck runs perfectly other than the idle surging but if i plug it in it only allows the truck to rev to maybe 2000RPMS and then it cuts out like a rev limiter. What is this sensor called? Also the idle speed motor on this engine is different than the ones on the montero, it's got a plastic screw on the end inside the intake that opens and closes whatever valve is connected to the mystery sensor. These two things obviously work together to control idle and cold starting. Any ideas?