Skylines AustraliaThe R32 GTR’s are supposed to idle at 950rpm. If the AAC is working correctly this will be the lowest the factory EPROM will allow it to idle. The work shop manual states that to set idle correctly, the AAC solenoid should be unplugged (or disabled via consult) and the idle speed should be set via the AAC idle adjustment screw to 900rpm. I guess this ensures the AAC solenoid regulates idle at the EPROM determined 950rpm. Of course if there is an issue such as a vacuum leak and the idle is artificially held above 950rpm then the ECU has no control (via the AAC) to regulate the idle. . If you have a consult program you can observe the AAC percentage vary to hold the idle at 950 rpm. Of course this only occurs at idle and only if the TPS idle switch point activates and provides the idle flag to the ECU. Again the consult will show the idle flag activate, followed by the AAC valve working to hold 950 rpm.