Vacuum Control Valve (VCV)
- Thermostatically controlled two-port and 4-port valves are closed when engine is cold. Valves open when engine is at operating temperature.
- For 3-port valves, with a cold engine, passage "A" to "B" should be closed and passage "A" to "C" should be open. See Fig 1
. With engine at normal operating temperature, VCV should be open between "A" and "B" and closed between "A" and "C".
- For 4-port valve, check "A1" to "B1" and "A2" to "B2" separately. See Fig 1
. If these conditions are not met, replace valve.
Courtesy of FORD MOTOR CO.