Idle Speed Switch

Fig. 30 Idle switch test. 1987-89:

1. Disconnect electrical connector from ISC servo with ignition off.
2. Check for continuity between connector terminal 2, Fig. 30, and injection mixer body (GND). Continuity should exist when throttle valve is in idle position and should not exist when throttle valve is opened.
3. If continuity is not as described, the ISC servo should be replaced.