The necessity of cleaning the throttle body and idle air control valve on a 2001 Ford F-150 is due to the positive crankcase ventilation valve located in the air duct just forward of the throttle body. The PVC valve allows a small amount of oil and mist to pass through the throttle body causing a coking of the throttle body and IAC. Coking is a sooty black buildup on these surfaces.
Remove the air duct between the air cleaner and the throttle body using the screwdriver. Unplug the electrical connector from the idle air control motor. This is the only round cylindrical mechanism on the side of the throttle body secured with two bolts. The two bolts are adjacent to the throttle plate.
Remove the two bolts in the idle air control using a socket. Remove the idle air control and the gasket beneath it. Spray carburetor cleaner on the pintle and shaft of the idle air control. The pintle is the cone on the end of the shaft used to regulate the airflow as it moves in and out. Try to clean off as much coking as possible. If oil has gotten into the motor through looseness in the shaft, replace the idle air control valve. The only way to tell if it needs replacing is to clean it and try it. If the idle is irregular after cleaning, it requires replacement.
Install the idle air control gasket and the control and tighten the bolts. Plug in the idle air control electrical connector. Start the engine. Hold the rpm at a fast idle using the throttle linkage on the side of the throttle body.
Spray the carburetor cleaner into the throttle body slowly so the engine does not stall. Use the entire can. Spray some cleaner in the two holes to the idle air control valve. The holes are on the same side as the idle air control valve. One hole is in front of the throttle plate and one behind. When the can is empty, shut off the engine.
Install the air duct and tighten it with the screwdriver. Start the vehicle and check for poor idle.
