Thermo-Time switch

The Thermo-Time switch regulates the amount of time the cold start valve is energized and prevents the opening of the cold start valve when the engine is warm. It is located on the underside of the intake manifold. The "thermo" section of the switch is a heater coil. When the starter is energized, current is passed through the thermo-time switch and into the cold start valve. As the current passes through the switch, a heater coil warms a bimetallic switch. It takes between 8 and 12 seconds for the heater coil to warm up to the point that it opens the circuit, preventing further fuel from passing through the cold start valve. (An important point to remember when troubleshooting starting problems with the cold start valve)
The length of time the circuit is energized (8-12 sec) is controlled by the coolant temperature, the longer it will take the heater coil to warm the bimetallic switch.