High idle rev w/ A/C on

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by letmusiclive, Jun 29, 2010.

  1. letmusiclive

    letmusiclive New Member

    Just got an 89 Sub with a 454 and the TH400. The thing is in great condition, with 88K on it.

    I noticed the other day that when the a/c is on, the engine has an abnormally high rev. You don't notice it much above 20-30mph, but when you are braking and get back down to first gear it feels like your foot is still on the accelerator.

    Any ideas as to what is going on?

    Thanks in advance!
  2. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    Sounds like your IAC is opening to try and idle the motor up for the higher load with the AC on.. You might try pulling it and cleaning it off...
  3. letmusiclive

    letmusiclive New Member

    Thanks! Now for a newbie question - where is it located at on the 454?

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