The Idle Air Control Valve (IACV) on a Ford Windstar is located on the
throttle body. The throttle body itself is usually situated on the intake manifold, near the engine's front. It's a relatively small valve, often cylindrical in shape, and may be hard to see without removing some components or at least carefully inspecting the throttle body. You'll likely need to refer to a repair manual specific to your Windstar's year and engine to pinpoint its exact location with a diagram.
Purpose:
The IACV's job is to control the engine's idle speed. When the engine is idling (not accelerating), the IACV regulates the amount of air entering the engine bypasses the throttle plate. This ensures a smooth and stable idle, even when other factors (like the air conditioning compressor) add load to the engine. If the IACV fails, you might experience rough idling, stalling, or difficulty starting the engine.
