Bi-Metallic Vacuum Solenoid Valve (BVSV)
Disconnect vacuum hoses from BVSV. Connect test hose to upper nozzle. With engine temperature below 127°F (53°C), air should not pass from upper nozzle through lower nozzle. With engine temperature above 149°F (65°C), air should pass from upper nozzle through lower nozzle. See Fig 1 .