Servo Diaphragm
1. Disconnect the vacuum control valve intake manifold vacuum sensing hose from tee fitting near the air control valve.
2. Disconnect vacuum line from vacuum control valve and connect line to tee fitting so intake manifold vacuum can be applied directly to the servo diaphragm.
3. Disconnect vacuum hose from distributor vacuum advance unit.
Fig. 28 - Deceleration Valve Test:
4. Start engine. The engine speed should rise to 1300-1500 RPM. If engine speed is not within specifications, adjust by turning adjusting screw on servo diaphragm throttle lever, Fig. 28.