Vacuum Delay Valves

Types Of Vacuum Delay Valves:

This valve, Fig. 23, further reduces emissions by delaying the spark advance during rapid acceleration and by cutting off advance immediately upon deceleration. This is a one-way valve and will not operate if installed backwards. On all systems which employ the dual diaphragm distributor, the line which has high vacuum at idle (normal operating temperature) is connected to the secondary (retard) side of the distributor vacuum advance unit. This is the connection closest to the distributor cap.