Throttle Opener System

Used in 1974 models and some 1976-78 models, this system opens carburetor throttle a slight amount during deceleration. It maintains balanced air/fuel mixture and reduces hydrocarbon (HC) emissions. System consists of servo diaphragm (mounted on carburetor), vacuum control valve, and connecting tubes and hoses. See Figure. Servo diaphragm is adjustable and operates on vacuum from vacuum control valve.