Abstract: A method and an apparatus for protecting an engine are disclosed which are capable of preventing damage to the engine or associated parts thereof. The engine is provided with an electronic control fuel injection system. A quasi-abnormality of at least one of variables in connection with the engine and the associated parts thereof, such as an engine cooling water, a fuel pressure or the like is detected by a sensor. When the quasi-abnormality of the variable and such a quasi-abnormal state lasts for a predetermined period of time, a throttle opening of an electronic control throttle is regulated so as to limit an engine rotational speed to a low rate.

Abstract: A method of controlling fuel injection is disclosed which enables highly accurate fuel injection and an enhanced durability of fuel injection valves in an internal combustion engine using an SPI system. The engine has a plurality of fuel injection valves disposed in an intake passage on an upstream side of a collector portion of an intake manifold of the internal combustion engine so that fuel is supplied to a plurality of cylinders of the engine by fuel injection from the fuel injection valves. The method includes alternately operating the plurality of fuel injection valves so as to supply the fuel when an intake airflow is a low flow rate equal to or less than a predetermined value, and simultaneously operating the plurality of fuel injection valves so as to supply the fuel when the intake airflow is a high flow rate more than the predetermined value.

Abstract: A method and an apparatus for protecting an engine are disclosed which are capable of preventing damage to the engine or associated parts thereof. The engine is provided with an electronic control fuel injection system. A quasi-abnormality of at least one of variables in connection with the engine and the associated parts thereof, such as an engine cooling water, a fuel pressure or the like is detected by a sensor. When the quasi-abnormality of the variable and such a quasi-abnormal state lasts for a predetermined period of time, a throttle opening of an electronic control throttle is regulated so as to limit an engine rotational speed to a low rate.

Abstract: A method of controlling fuel injection is disclosed which enables highly accurate fuel injection and an enhanced durability of fuel injection valves in an internal combustion engine using an SPI system. The engine has a plurality of fuel injection valves disposed in an intake passage on an upstream side of a collector portion of an intake manifold of the internal combustion engine so that fuel is supplied to a plurality of cylinders of the engine by fuel injection from the fuel injection valves. The method includes alternately operating the plurality of fuel injection valves so as to supply the fuel when an intake airflow is a low flow rate equal to or less than a predetermined value, and simultaneously operating the plurality of fuel injection valves so as to supply the fuel when the intake airflow is a high flow rate more than the predetermined value.