Cleaning the Idle Air Control Valve

The Idle Air Control (IAC) valve assists the engine at idle speed. It adds a little more air and leans out the air/fuel mixture. At low rpm, the EFI has trouble controling the idle speed.

If you have the following symptons then you should try cleaning your Idle Air Control (IAC) valve.

  • Rough idle
  • Engine bogging at take off
  • Engine bogging at low rpm
  • Engine bogging when turning a corner

This tip is from Lonnie F:

I did find another problem that others may have had. My truck had a rough idle and like I said would bog. It would bog at take off, cruising at a low rpm, and if I was turning a corner. What I found was that the idle air control valve was gunked up and not working like it should. I didn't notice it really w/ the 14 lb injectors but the 19 lb injectors need a little more air at idle and even though I adjusted the idle screw the computer was fighting it's self. Anyways I removed the valve and completely cleaned the inside where the plunger is with throttle body cleaner. Then I sprayed the spring and plunger with wd-40. Once I put it back on and reconnected the battery it only took a couple of seconds to find it's idle and learn it. I've drove a full day yesterday in it putting over 100 miles on it. And it runs perfectly without bogging or any hesitation. Maybe others were like me and started having a sticking IACV but didn't realize it until the larger injectors were in place. By the way I love how this truck accelerates now. It's so much more fun and easier to drive.

Cleaning your Idle Air Control valve

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Copyright February 2011 Eugene Blanchard