Fast Idle Servo Diaphragm (Federal Models)
- Bring engine to operating temperature. Remove air cleaner and plug hoses to idle compensator, thermosensor and reed valves. Connect tachometer and disconnect vacuum hose from fast idle solenoid-to-servo diaphragm at diaphragm.
- Apply intake manifold vacuum directly to servo. Increase engine speed to 2000 RPM, then release throttle. Engine speed should be within 1200-1400 RPM. Turn adjusting screw to obtain correct RPM.