Eagle Sedan L6-258 4.2L (1984)
Electric Assist Choke: Description and Operation
The electric assist choke reduces carbon monoxide (CO) and hydrocarbon (HC) emissions during warm-up. It provides supplemental heat to the choke
bi-metal to speed up choke valve opening after the choke cover interior reaches a pre-determined temperature.
Fig. 13 Electric choke assembly. 4-150 & 6-258 engines
4-150 & 6-258 ENGINES
On this system, Fig. 13, a special tap is provided on the alternator to supply power to the electric assist choke. A thermostatic switch within the choke
cover closes when the interior of the choke cover reaches the modulating temperature. This allows current to flow to the heating element when the circuit
is completed through the choke cover ground strap and choke housing to the engine. As the heating element becomes hot, heat is absorbed by an attached
metal plate which heats the choke bi-metal coil. When the engine is turned off, the thermostatic switch remains closed until the choke cover interior
modulating temperature is reached. If the engine is started immediately after shut-down and before the modulating temperature is reached, current will
immediately begin warming up the heating element to open the choke. Once the choke cover interior temperature falls below the modulating temperature,
the thermostatic switch opens and current flow to the heating element is shut off. If the engine is restarted at this time, the electric assist function will not
operate until choke cover interior reaches its modulating temperature.
