[Roadster]

This is directly from Marc Haibeck's website.... zr1specialist.com

"High idle speed is most commonly caused by a vacuum leak. The throttle body can cause a high idle if a throttle plate binds with a bore.*If the high idle is intermittent or goes away when the accelerator pedal is kicked, the high idle is caused by the throttle body. If a light tap fixes the idle, the problem is with the primary throttle. If a hard kick to 25% throttle or more helps, the problem is with the secondary throttles."

Hope this helps....