A control device is shown for a fuel supply system for an automotive engine having a heater which is energized, deenergized and then reenergized in sequence to heat a thermostat metal coil spring over a selected temperature range to regulate opening of a carburetor choke during engine warm up. Contacts are connected between a power source and the heater and a pair of dished bimetal elements having central apertures therein are arranged in facing relation to each other between the contacts, the bimetal elements being adapted to move to inverted dished configuration as they are heated to respective different temperatures within the noted temperature range. The contacts are engaged with each other through the element apertures when engine operation is initiated, are separated when one of the elements moves to its inverted configuration in response to heating of the element, and are then reengaged as the second element moves to its inverted configuration in response to further heating.
