Abstract: If an alcohol sensor which determines the amount of alcohol which is mixed with gasoline, malfunctions, the fuel supply correction factor which is designed to modify the basic fuel supply amount to compensate for the amount of alcohol, is prevented from being changed in accordance with the output of the alcohol sensor, and temporarily calibrated by feedback from the air-fuel ratio sensor disposed in the exhaust system.

Abstract: An apparatus for use with an internal combustion engine operable on either of gasoline fuel and gasoline/alcohol fuel blend. The apparatus comprises an alcohol concentration sensor for sensing the alcohol concentration of the fuel to be delivered to the engine, an oxygen sensor sensitive to the oxygen content of exhaust gases discharged from the engine for producing an air/fuel ratio feedback signal, and a control unit coupled to the alcohol concentration sensor and the oxygen sensor for controlling the amount of fuel metered to the engine. The control unit calculates a basic value for the amount of fuel metered to the engine based on engine operating conditions and corrects the calculated basic value for the sensed alcohol concentration. A correction factor, which is set within a control range defined by predetermined upper and lower limits, is calculated based on a deviation of the air/fuel ratio from a stoichiometric value.

Abstract: A fuel system includes a motor-driven pump which pressurizes a source of fuel to a predetermined pressure level and delivers the pressurized fuel to an engine-driven pump which, in turn, communicates with high-pressure fuel injectors for supplying high-pressure fuel into respective cylinders of an engine during normal engine operation. A low-pressure fuel injector is provided which is connected to the discharge side of the motor-driven pump for supplying low-pressure fuel into an engine intake manifold near its entrance only during the engine is being cranked.

Abstract: A fuel supply system of an internal combustion engine for an automotive vehicle, comprising engine load detecting means operative to detect load on the internal combustion engine and to produce an output signal representative of the detected engine load; an electrically-operated fuel-injection nozzle assembly projecting into a combustion chamber of a power cylinder of the engine and operative to inject fuel into the combustion chamber; and an electric control unit electrically connected to the engine load detecting means and the fuel-injection nozzle assembly and operative to produce control signals to determine the durations of fuel injection and the fuel injection timings of the nozzle assembly on the basis of the signals, the fuel injection timings being determined to occur in the presence of a relatively low gas pressure in the combustion chamber.

Abstract: An electronically controlled fuel injection system for an internal combustion engine which determines the pulsewidth of a drive signal to be applied to a plurality of fuel injection valves, each located within an intake manifold, which in turn determines the fuel injection amount per engine revolution according to the engine operating conditions, the air-fuel mixture ratio being smoothly changed from a lean air-fuel mixture ratio to a richer air-fuel mixture ratio when the engine load changes from a partial load to a full load. Therefore, fuel consumption is remarkably reduced without worsening the handling of the vehicle in which the fuel injection system is incorporated.

Abstract: In order to improve the cold starting efficiency of a an internal combustion engines using alcohol or low cetane type fuel, an ignition method provides an ignition mode in which a plurality of energizations of the ignition plugs per cycle is effected during engine cold starting operation which is detected by sensing at least one of the engine temperature and the engine speed. The number of energizations per cycle is returned to one after the engine has sufficiently warmed up. The method is applied to both of a plasma ignition system and a conventional spark ignition system.