THERMO-Time Switch

For cold starting, additional fuel is injected into intake manifold by the cold start injector (valve). This cold start aid is controlled by the thermo-time switch. The switch has a bi-metal contact, surrounded by a heating coil which is energized during cranking. Thermo-time switch limits cold start relay to 5-20 seconds under extreme cold engine starts. When engine coolant temperature is above 95°F (35°C), bi-metal contact breaks ground circuit of cold start injector (valve) and cold start enrichment is by-passed.