Spark Timing Control System
This system, used on models with automatic transmission only, uses a dual point distributor to provide an "Advanced" and "Retarded" ignition setting. The difference between these two timings is 10° at the crankshaft. The "Advanced" timing is used to give optimum engine performance at low temperatures, while "Retarded" position helps reduce exhaust emissions. Retarded points operate whenever passenger compartment temperature is over 41-52°F, while advanced set only operates at temperatures below 30°F. Operation of retarded points is controlled by a thermo switch which operates through a relay.