Feedback Control Solenoid: Description and Operation

Since this system requires more precise fuel metering for efficient operation then is possible with a conventional carburetor, Electronic Feedback Carburetors, Holley model 6520 is used on four cylinder engines.
The feedback solenoid provides limited regulation of the air-fuel ratio on a feedback carburetor in response to electrical signals from the Spark Control Computer. It performs this task by metering air flow and operating in parallel with a conventional fixed main metering jet.