atc98092· Super Moderator
2022 Bolt EUV Premier: sold back to GM Jan ‘23
What you were seeing is the carburetor activating the accelerator pump, which adds some additional atomized fuel into the airstream to assist the engine with a rapid change of the throttle valve. Otherwise the engine would momentarily bog down until the airflow through the venturi would increase enough to properly fuel the engine with the quick increase of air volume. Under most conditions, the air passing through the venturi causes a vacuum that pulls the fuel through the different valves and ports to properly mix the fuel and air. Moving to fuel injection eliminated all of those less precise mechanical functions, increasing power and economy while reducing emissions.I had a 1983 Mustang and I've removed the cap on the carburetor before and saw how the gas pedal directly produces a gas mist.