Vacuum Control Valve

Testing 2 And 4-Port Regulator Valves:

2-Port Vacuum Check
Applying vacuum to Port A, while the engine and sensor are cold, should produce the OPPOSITE results, at Port B, as to when the engine and sensor are warmed and vacuum is applied.

4-Port Vacuum Check

The 4-Port valve is equal to two separate 2-Port valves that share the same thermal sensor.
Applying vacuum to Port A1 and A2, while the engine and sensor are cold, should produce the OPPOSITE results, at Port B1 and B2, as to when the engine and sensor are warmed and vacuum is applied.


Switching Temperature for 2 & 4-Port Control Valves

Color Code Closed Below Open Above
Brown or Black 80~F (27~C) 95~F (35~C)
Green or Blue 103~F (39~C) 128~F (53~C)
Yellow 135~F (57~C) 160~F (71~C)
Natural 70~F (21~C) 85~F (29~C)
Gray 125~F (52~C) 150~F (66~C)



3-Port Vacuum Check

Testing 3-Port Regulator Valves:

1. With cold engine, vacuum applied to Port A (center port) should leak from Port C (upper port).
Vacuum should NOT leak from Port B, if Port C is plugged with finger.

2. With warm engine, vacuum applied to Port A (center port) should leak from Port B (lower port).
Vacuum should NOT leak from Port C, if Port B is plugged with finger.



3-Port Electrical/Vacuum Check

Electrical Vacuum Control Valve Switch:

1. With cold engine, vacuum applied to Port A (center port) should leak from Port C (upper port).
Vacuum should NOT leak from Port B, if Port C is plugged with finger.
2. Measure the resistance between the the electrical terminals.

3. With warm engine, vacuum applied to Port A (center port) should leak from Port B (lower port).
Vacuum should NOT leak from Port C, if Port B is plugged with finger.
4. Measure the resistance between the the electrical terminals.

NOTE: The 3-Port Electrical Vacuum Switch could be opened or closed on a cold engine. After the engine warms up to operating temperature, the valve will be in the reversed position (closed or opened).