imsolidstate

Electronic choke

When I had carbureted vehicles, I always hated the choke spring. They never worked right, no matter how much you twiddled with them. They either never pulled all the way off or never closed enough to start on that really cold day when it’s so much fun to adjust chokes.
I thought the design could use some modernization, so I designed a true electric choke. Or maybe electronic choke is more accurate, because “electric choke” just means a heater mounted to the bi-metallic spring.

I used a servo to command a certain choke position, and I designed a simple spring mechanism so that the servo wouldn’t burn itself up trying to get to a position when the throttle was closed and the position of the fast idle cam can’t be adjusted. I didn’t have my CNC machine running at the time or I would have made a housing and ordered a smaller servo so that it all had about the same appearance of an electric choke, except for an extra wire. That extra wire would go to a temperature sensor in the coolant circuit.

I would have also added a dip switch for making adjustments to choke pull off points based on engine temperature. If I ever have another carbureted vehicle I might finish it.

Tags: Choke, Servo