1979 Models (Servo Diaphragm Test)
- Connect tachometer to engine. Start and warm engine to normal operating temperature. Stop engine and remove air cleaner.
- Detach intake manifold vacuum hose from 3-way solenoid and detach 3-way solenoid vacuum hose from servo diaphragm. Connect intake manifold vacuum hose directly to servo diaphragm.
- On 626, detach and plug distributor-to-carburetor vacuum tube at distributor. On all models, start engine. Increase engine speed and allow speed then decrease to idle.
- With servo diaphragm hooked directly to intake manifold, engine should idle at 1000-1100 RPM. If vehicle is equipped with air conditioning, it will idle at approximately 1200 RPM.
- If speed is not to specifications, turn throttle positioner adjusting screw located on linkage near end of servo diaphragm link on carburetor. If setting cannot be obtained, replace servo diaphragm.