- Start the engine and allow it to idle.
- Separate the connector at the distributor solenoid valve and apply battery
power to the terminals to energize the valve.
- Disconnect the vacuum hose from the vacuum advance unit. There should be
no vacuum at the hose.
- Remove the battery power to the solenoid valve. The valve is operating properly
if air is drawn (by vacuum) into the vacuum hose as soon as power is removed.
