Control system for internal combustion engine

A control system for controlling an internal combustion engine having intake and exhaust valves and a fuel supply unit for supplying fuel into an intake port which is openable and closable by the intake valve, said intake valve being the sole means of controlling the amount of charge from atmosphere into the combustion chamber, said control system comprising:

• electromagnetic actuator means for selectively opening and closing the intake and exhaust valves;
• a fuel injection nozzle for injecting fuel from the fuel supply unit into the intake port;
• an engine load sensor for detecting a load on the internal combustion engine;
• a crankshaft angle sensor for detecting an angular position of a crankshaft of the internal combustion engine;
• first calculating means for calculating timings to open the intake and exhaust valves based on detected signals from said engine load sensor and said crankshaft angle sensor;
• second calculating means for calculating an amount of opening of the intake valve to introduce an amount of intake air which achieves a stoichiometric air-fuel ratio corresponding to the load on the internal combustion engine based on a detected signal from said engine load sensor;
• third calculating means for calculating an amount of fuel to be injected and a timing to inject fuel based on detected signals from said engine load sensor and said crankshaft angle sensor;
• first control means for applying drive signals to said electromagnetic actuator mans based on the openings and timings calculated by said first and second calculating means;
• and
• second control means for applying a control signal to the fuel supply unit based on the amount and timing calculated by said third calculating means.