Often referred to as T.C.S. Solenoids, these solenoids control vacuum to the distributor vacuum advance unit. The solenoid determines when and how much vacuum to release. Typically a vacuum line from the carburetor enters the solenoid and another vacuum line exits the solenoid to the distributor vacuum advance unit (some applications have multiple inlet and outlet lines). The solenoids also rely on an electrical signal provided by other T.C.S. system switches/senders via an electrical connectionon the back or side of the solenoid (the Engine Harness or T.C.S. Harness plugs into this connection).
Introduced in 1970, the Transmission Controlled Spark System controls exhaust emissions by eliminating vacuum advance in the lower forward gears while at operating temperature.
Electrical components such as solenoids are non-returnable parts.
Always refer to a factory service manual when diagnosing engine service problems. You can damage electrical components if the proper procedures are