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TCS Solenoid w/ Bracket
Original price was: $99.00.$95.00Current price is: $95.00.
TCS Solenoid w/ Mounting Bracket
Fits 1970 – 1972 Buick Engines (And probably many others)
Here’s GM’s answer to what this was designed to do:
Transmission Controlled Spark (TCS) Solenoid
- Purpose: To reduce exhaust emissions (specifically nitrogen oxides, or NOx) during cold operation or while driving in lower gears.
- Operation: Mounted externally on the engine or intake manifold rather than inside the transmission, this vacuum-switching solenoid was triggered by a pressure switch inside the transmission.
- Function: When the transmission was in 1st or 2nd gear, the solenoid blocked full intake manifold vacuum from reaching the distributor’s vacuum advance canister, retarding the ignition timing to lower combustion temperatures and reduce smog during city acceleration. Once the transmission shifted into high (cruising) gear, the switch allowed standard vacuum advance to return for better highway fuel efficiency.
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