Throttle Closure Delay System

If system does not function correctly and throttle diaphragm unit is adjusted properly, disconnect vacuum line from throttle diaphragm unit and check for vacuum. If vacuum is present but plunger does not operate, replace throttle diaphragm unit. If no vacuum is present, check for leaky hoses and connections and make sure speed relay is properly grounded. Unplug lead to two way valve and connect voltmeter. With engine speed above 2000 RPM, if reading is 12 volts, replace valve. If reading is 0 volts, replace speed relay.