Servo Diaphragm
- Check hoses for proper routing and condition. Start engine and set idle speed. Turn engine off, detach vacuum hose from distributor and plug hose.
- Disconnect vacuum line at vacuum amplifier and vacuum hose at 3-way solenoid. Connect vacuum hose from servo diaphragm to vacuum amplifier so intake manifold vacuum is applied directly to servo diaphragm.
- Connect tachometer to engine. Start engine and idle. Note that engine speed should increase to 1000 RPM for Federal vehicles or to 1100 RPM for California vehicles.
- If not, adjust engine speed by turning adjusting screw on servo diaphragm throttle lever until proper speed is obtained. See Fig 1. Reconnect all hoses to original position.
Courtesy of FORD MOTOR CO.