Electric Assist Choke: Description

Some vehicles are equipped with an electrically assisted choke thermostatic spring heater to aid in fast choke release and to improve emission characteristics. Two types of chokes are used, a temperature sensitive type and a constant operating type. Both types operate from current supplied from the center tap of the alternator when the engine is running.

The temperature sensitive electric assist choke system consists of a choke cap, thermostatic spring, a bi-metal temperature sensing disc (switch), and a ceramic positive temperature coefficient (PTC) heater. The all-electric choke has 2 of these "heating pills", the second of which is turned on when the temperature is rising (54° to 74°F).

The constant operating type choke system consists of a choke cap, bi-metal spring, choke heater and a vacuum diaphragm and spring.