erratic/wavering idle problems with 91 montero

Need help! I have a 91 Montero that has been great! However, it has been acting up on us. For some reason, the idle is going all over the place when it's sitting in idle. By this, I mean, it revs over 2,000 rpm, and then drops almost the point where the engine cuts off. The problem normally starts up after the engine's been running for a while. My wife's told me it actually caused the car to lunge on her, nearly hitting another parked in front of her. I had a similar scenario, except it was in the driveway, and the brakes weren't working either. Thank God the e-brake worked, or my shed woulda been toast! lol I've tried resetting the idle speed adjustment, and that didn't seem to do much. It did fix the problem for a while. But, it hasn't gone away for good. Anyway, if anyone has any ideas, I'd love to hear them. It's an LS, with a 3L V-6, if that makes any difference...

Reply to
boardincuban
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  1. Check for vacuum tube leaks
  2. Check the Air Idle Motor connections and measure the resistance of the motor coils. This is the device that sits on the side of the throttle body and adjusts the throttle opening at idle.
  3. Clean the throttle body.
  4. Check the connections to the air filter (ie the MAS inside it).
  5. Take the Air Idle Motor off, and CAREFULLY open it. There's some plastic gears inside that often chew themselves up when the throttle shaft gets stuck with fuel gum.
  6. Start looking for another throttle body.
Reply to
Stewart DIBBS

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