Vacuum Solenoid Valve Test
- With engine at normal operating temperature, engine idling and transmission in neutral, make sure choke plate is fully open.
- Turn off air conditioner, power take-off (if equipped) and all accessories. Disconnect vacuum supply hose at solenoid valve and check for vacuum. If no vacuum is present, clean or replace hose as required.
- If vacuum delay valve is used, remove valve and install straight connector. Disconnect wires to solenoid valve. With jumper wire, apply battery voltage to one of the solenoid terminals. Engine speed should not increase. If it does, replace solenoid valve.
- With battery voltage on one terminal, use second jumper wire to ground other terminal of the valve. Engine speed should increase, if not, replace valve.
- Remove ground jumper wire. Engine should return to idle within 15 seconds. If not, replace solenoid valve.