Vacuum Advance Control Solenoid: Description and Operation

The vacuum advance VSV (vacuum solenoid valve) blocks the vacuum source to the advance diaphragm during cold start and engine warm-up periods. The vacuum ports are closed when the solenoid is energized. The solenoid is connected in parallel circuit with the EFE heater, to the EFE relay, so it is energized and de-energized simultaneously with the EFE system