Vacuum Advance Control Solenoid: Testing and Inspection

Fig 50 Vacuum Solenoid Valve:

1. Connect vacuum to port 2 of valve, Fig. 50.
2. Start engine and turn off A/C.
3. Manifold vacuum should be indicated on gauge.
4. Turn on A/C and accelerate engine. Ported vacuum should be indicated on gauge.
5. If operation is not as described above, replace valve.