Re: 70 Nova TCS Relay
Bob you asked...
TCS=Transmission Controlled Spark.
New for 1970 cars and Series 10 Trucks.It was designed to provide Vacuum Spark Advance during Hi-gear operation only.
Elimination of Vacuum advance in all but the forward gears,greatly reduces exhaust emissions.
It consists of:
*A Vacuum Control valve mounted on the intake.
*A Transmission control switch mounted on the trans.
*A coolant temperature switch mounted on the passenger side of the head.
The item on the firewall is merely a relay.
During operation the valve controls the Vacuum Advance to the Distributor,in response to a signal from either switch.This also hurt Horsepower,so we all pitched it upon taking ownership of the new MuscleCar.
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