Exhaust Emission Systems - ALFA Romeo: Operation

Fuel is injected into each intake duct near intake valves by means of four pumping elements. Fuel delivery rate from pumping elements is regulated by a control unit on injection pump. A cam in control unit provides correct quantity of fuel delivered according to throttle opening and engine speed. Normal fuel delivery is varied by compensating devices, giving proper correction for changes in engine temperature, atmospheric pressure, cold starting, initial running, and fuel cut off during deceleration. With the aid of fuel injection compensating devices, and modified ignition distributor, exhaust emissions are maintained below maximum permissible levels. See Alfa Romeo Spica Fuel Injection in CARBURETION Section  .