Abstract: Disclosed is a fuel injection control apparatus wherein the quantity of fuel supplied to an internal combustion engine is derived from engine operating parameters including a voltage signal which is generated by electromagnetic induction as a function of engine speed. A fuel injection quantity calculation circuit derives the fuel quantity in accordance with the detected operating parameters of the engine. A fuel injection controller provides injection of fuel in accordance with the calculated fuel quantity when the sensor voltage is valid and provides forced fuel injection regardless of the calculated fuel quantity when the sensor voltage is invalid and the engine starter is being operated.

Abstract: A high-pressure fluid control solenoid valve assembly for use with a spill type fuel injection pump of an internal combustion engine, comprises an actuator portion (101) including a solenoid (8, 9), a stator (7) and an armature (14), and a valve portion (102) including a pilot valve (40, 41) and a main valve (42, 43) where the valve portion (102) is spaced apart from the actuator portion (101) and is responsive to the movement of the armature (14) via a rod (14) connected to the armature (14) and extends axially in a bore of the stator (7) which is cylindrical hollow. The pilot valve (40, 41) is coaxial with and telescopically received in the main valve (42, 43) so that two fluid chambers (54, 51) are formed inside and outside, respectively a spool (42) of the main valve such that the main valve is continuously kept closed irrespective of the fluid pressure in these chambers as long as the pilot valve is closed.

Abstract: In controlling a fuel injection quantity by an electromagnetic spill valve on-off operated at a target spill angle in accordance with an angle count number and a time count number of an engine rotation, based on the engine rotation angle signal outputted through a predetermined crank angle, the angle count number is set at a predetermined value during idling and time count is constantly started from one and the same point of on-off operate the electromagnetic spill valve. In consequence, the control of the fuel injection quantity does not fluctuate during idling irrespective of various factors of dispersion. On the other hand, during non-idling, the angle count number varying in association with the target spill angle is determined and the time count is started from the end point of the angle count number to control the electromagnetic spill valve. In consequence, an adverse influence suh as an engine stall is not rendered to the normal operating conditions.

Abstract: A method and apparatus for controlling the fuel injection timing of a compression ignition engine are featured by dithering the fuel injection timing so as to be advanced and retarded with respect to and in the vicinity of a calculated timing of injection of pressurized fuel supplied to the engine which calculated injection timing is determined in accordance with operating conditions of the engine, operating the engine alternately at the calculated fuel injection timing, the advanced fuel injection timing and the retarded fuel injection timing each during a given period of time, deciding a direction of improving a fuel consumption rate of the engine from corresponding changes of an operating condition of the engine detected when the engine is operated at the respective fuel injection timings, and correcting the calculated fuel injection timing in accordance with the result of the decision, thereby controlling the fuel injection timing at an optimum fuel injection timing which ensures an optimum fuel consumpti