Cold Start Fast Idle System

During cold start, a rich air/fuel mixture and a fast idle speed are required to maintain driveability. Cold start choke system utilizes a wax-pellet type choke activation mechanism to open and close choke, as well as activate and deactivate cold fast idle cam.

When wax pellet is cold, it is in the contracted state, allowing choke valve to close and fast idle cam to rotate to the high step of cam. As vehicle warms up, wax pellet gradually expands, pushing down on fast idle cam, while at the same time opening choke valve. As choke valve opens, it is assisted by a choke opener diaphragm connected to upper choke valve linkage.