Deceleration Fuel Cut-Off System: Operation
Deceleration system relay is activated only when coolant temperature is above 113°F (45°C), relay switch is in rest position and engine speed exceeds 1400-1750 RPM. When throttle switch closes, system will operate until engine speed decreases below 1300-1475 RPM.
When system operates, flow of air is led through by-pass hose and vacuum valve instead of passing air flow sensor plate. Air flow sensor plate drops to rest position, which cuts off fuel to cylinders.