This test can be performed on a warm engine.
1. With the engine off, connect the tachometer.
2. Disconnect and plug the fast idle ejector internal vacuum hose.
3. Operate the fast idle cam by fully opening and closing the throttle while keeping the throttle blade closed.
4. Start the engine. The fast idle speed should be 2000-3000 rpm.
5. If necessary, adjust the speed with the adjusting screw.