Temperature time switch in intake manifold / intake bridge Fiat 124 Spider from 1980 onwards

The temperature-time switch is responsible for controlling the cold start valve.

The temperature-time switch limits the injection duration of the cold start valve depending on the engine temperature. It is housed in a hollow threaded bolt, which is attached at a point characteristic of the engine temperature.

When the engine is cold, the temperature-time switch is closed, allowing the cold start valve to inject fuel. When starting a warm engine, however, the switch is open, preventing additional fuel injection.

Furthermore, the maximum injection duration of the cold start valve is limited to prevent the engine from becoming over-fueled and flooding.

The remanufactured temperature-time switch has an electronic component and is therefore largely wear-free.