How to Clean Carbon Buildup in an IAC Valveby Johnathan Cronk
The idle air control valve, commonly referred to as the IAC valve, is responsible for adjusting idle speed. The IAC valve works closely with other electrical components to control the air moving around the throttle plate. If your vehicle begins to stall or has poor idle quality, your IAC valve may have carbon buildup and needs to be cleaned. Cleaning your vehicle's IAC valve is a simple task and only takes a few steps.
Allow your vehicle to cool for 20 minutes before beginning any work.
Refer to your owner's manual for the exact location of the IAC valve in your vehicle. The IAC valve us normally near the throttle body.
Unplug the wiring harness connector using a flat head screwdriver to pry the snaps off. Using a socket wrench, unscrew the bolts holding the IAC valve into the block.
Examine the IAC valve; the needle part of the valve is normally where the carbon buildup is. Use carburetor cleaner to spray the needle and wipe the needle clean using a rag. Repeat this until the carbon buildup is cleaned off the needle. Allow the IAC valve to dry completely before reinstalling it.
Insert the IAC valve back into the block and tighten the two bolts. Plug the wire connector back into place. Start the vehicle and allow it to warm up for five minutes before driving it.