Idle Speed Controller With Integral Tracking Switch

To check idle speed controller portion, connect a hand operated vacuum pump to vacuum connection. With vacuum applied, the switch should extend and hold, and must take longer than 10 seconds for vacuum to drop from 20 inches Hg to 10 inches Hg.
To check idle tracking switch portion, check for continuity at electrical connection, when throttle stop lever is against switch, and switch is open. There should be no continuity.