Where is idle air control valve located on a 1991 Chevy s-10 4.3l?

The Idle Air Control (IAC) valve on a 1991 Chevy S-10 with a 4.3L V6 engine is typically located on the throttle body. It's a small, usually cylindrical, valve mounted directly to the throttle body, often near the base where the throttle body connects to the intake manifold.

To be absolutely certain, you should:

1. Consult a repair manual: A Haynes or Chilton repair manual specific to your year and engine will have a diagram showing its precise location.

2. Use a parts diagram: Online auto parts stores (like AutoZone, Advance Auto Parts, etc.) let you look up parts diagrams for your specific vehicle. Finding the throttle body and then zooming in will show you the IAC valve.

Because there can be slight variations depending on the exact configuration of your vehicle's engine compartment, using a visual guide is the most reliable way to locate it.