How to Adjust Electric Choke on an Edelbrock Carbby Jack Hathcoat
Edelbrock manufactures carburetors for classic cars and street performance machines. They offer two basic models that fit a large number of engine sizes made by different manufacturers. To accommodate cold starting requirements where additional fuel is needed, Edelbrock provides manual choke setups and electric choke designs. The manual choke has a dash-mounted knob that operates a cable to open and close the choke plate, while the electric version uses a electrically heated coil that expands as it heats to open the plate.
Open the hood of the car and remove the air cleaner. On the right side of the carburetor, locate a black, round disc held in place by three screws. Two wires are plugged into the disc and provide power to heat the internal coil that expands and contracts to open and close the choke plate.
Loosen the screws, but do not remove them. On top of the choke are index marks, and the factory preset is midway between the marks. If the choke is indexed further to the right, the engine will receive more fuel when it is cold. If it is moved left, it receives less fuel. Adjust the choke according to the way the car runs when it is cold. If it stumbles and backfires, it is too lean and needs more fuel. If it bogs down and is non-responsive under acceleration, it is too rich and needs less fuel.
Tighten the screws and test-drive the car. The only way to tell if the choke is set properly is trial and error. If the car runs properly after setting the choke, no further adjustments are needed, however, if the performance is still lacking, wait several hours for the engine and choke coil to fully cool before making further adjustments.
- Before declaring the choke adjustments complete, the definitive test is the test-drive the next morning. After the car has sat overnight, the engine has lost all heat-soak from being driven the previous day. The temperature has dropped overnight, and adjustments made the following day may not meet the requirements of early morning start-up. Readjust as necessary.
Things You'll Need
- Screwdriver set
Jack Hathcoat has been a technical writer since 1974. His work includes instruction manuals, lesson plans, technical brochures and service bulletins for the U.S. military, aerospace industries and research companies. Hathcoat is an accredited technical instructor through Kent State University and certified in automotive service excellence.