How to Clean the IAC in a Dodge Caravanby Don Bowman
The idle air control mechanism (IAC) on a Dodge Caravan is designed to provide sufficient air to control the engine’s idle under different load and atmospheric conditions. When the gas pedal is depressed, a large round plate in the throttle body opens to allow a corresponding amount of air into the engine to regulate speed. When the throttle is closed no air can pass this plate. To maintain an idle there are two holes in the throttle body, one in front of the plate and one behind. The idle air control is the small round electrical device that uses a pintle, which is a 3/8-inch rod with a beveled end. This rod moves in or out of this hole allowing more or less air into the engine controlling the idle. An irregular idle speed can usually be contributed to the IAC. It can sometimes be cleaned, instead of replaced.
Raise the hood and remove the air duct to the throttle body, using the screwdriver. Disconnect the electrical connector from the idle air control.
Remove the two bolts securing the idle air control to the throttle body, using the appropriate socket. Pull the idle air control out of the throttle body.
Hold the idle air control mechanism so the pintle is pointing toward the ground. Spray the pintle with carburetor cleaner. Do not allow the carburetor cleaner to run down the pintle into the electrical body of the idle air. Wipe the pintle with a rag. Repeat until all carbon buildup has been removed from the pintle. Dry the pintle off. Make sure the holes in the intake manifold, exposed when the IAC was removed, are clear of carbon.
Slide a new O-ring on the idle air control. Do not coat the O-ring with anything or it will not seal properly. Install the idle air control by pushing it in until the O-ring seats. Make sure that the electrical socket is facing in the proper direction.
Install the two bolts and tighten with the same socket. Plug the electrical connector into the idle air control.