Lee, Check to see if the throttle body lever is going all the way down and it isn't binding. Also, make sure the ground and the hot on the switch is working ok. You can check that with an ohm meter or a light with wires. If that seems to be all ok, the the idle speed thermister in the internal water pipe may not be sending the signal up to the ECU or the connector may have come off in all the working. The only other thing to check on top, is the idle speed motor turning the cut off in the tube. John Hervey www.specialTauto.com