According to the service manual you need a scan tool to set the IAC to 0 steps then you set the base idle. I dont have a scan too so I guessed at getting it to 0 using procedure below. 1 Turn the throttle stop screw until 1000rpm in Park on Neutral 2 Disconnected the IAC. 3 Turn the throttle stop screw until 450-550 RPM in Park or Neutral 4 Shutdown engine and reconnect IAC 5 Start Engine and run for 5 seconds 6 Turn off Engine for 10 seconds 7 Restart engine and check for proper idle.
All but step 1 is from the service manual. Section 6C1-3 Service Operations 3.11 Fuel Control System Throttle Stop Screw - Check or Reset That is true but the question was how to set the base idle not how to reset the IAC, the base idle is contolled by the throttle stop screw not the IAC.
Base idle would be virtual at best wouldn't it? The IAC is the tool of the ECU to keep the revs at the preset value in the tune. The idle screw is irrelevant really because to a point the IAC will over ride that setting anyway
Yes that is true, the base idle is the minimum idle speed you would see if the IAC is fully closed (0 steps) the ECU expects the base idle to be set to 450-550rpm and knows roughly how many steps it needs to maintain the desired idle speed, if the base idle is wrong, ie too low then you may get a bit of stumble when going off throttle until the ECU adjusts the IAC count, depends how far out it is. If the base idle is too high then the IAC wont be able to bring it down to the desired speed, ie if the IAC goes down to 0 counts and the idle speed is still to high.
