Fuel Control Operation - CARBURETED Models

All carbureted vehicles are equipped with a 4-Bbl. "feedback" carburetor using an electric Mixture Control (M/C) solenoid. See Fig 1 . The M/C solenoid operates a metering rod system in the float bowl which supplements fuel supplied by idle and main systems in carburetor to vary air/fuel ratio within a pre-calibrated range. The M/C solenoid also controls air/fuel ratio through use of an idle air bleed that operates in conjunction with metering rod system.

Fig 1: Sectional View of Mixture Control Solenoid

Courtesy of GENERAL MOTORS CORP.