Appropriate detection of an abnormality of voltage information, which is a basis for correcting a fuel injection amount, becomes possible. For this reason, a fuel injection control device 127, which has a drive IC 208 controlling a fuel injection drive unit 207a to supply a high voltage to a solenoid 405 so as to open a fuel injection valve 105 and controlling the fuel injection drive unit 207a to supply a low voltage to the solenoid 405 so as to hold a valve-open state of the fuel injection valve 105, includes: a drive voltage input unit 211 that measures and outputs voltage information based on an upstream voltage of the solenoid 405 of the fuel injection valve 105 and a downstream voltage of the solenoid 405; a fuel injection amount correction unit 213 that corrects a fuel injection amount of the fuel injection valve 105 based on the voltage information output from the drive voltage input unit 211; and a voltage input function abnormality detection unit 212 that detects whether an output of the drive voltage input unit 211 is abnormal based on the voltage information output from the drive voltage input unit 211.

An injection control device includes a control IC that obtains, as sample data, a time change of a voltage generated when a fuel injection valve is driven, and determines a valve closing timing at which injection of fuel from the fuel injection valve is stopped by calculating a degree of variation from the sample data of the voltage. Further, the control IC changes the calculation of the degree of variation when a predetermined condition is satisfied.

A method for operating the two stroke engine provides that the fuel valve is controlled after the starting process in at least a quasi-steady state such that, on the basis of uninterruptedly successive blocks of successive revolutions of the crankshaft, the fuel valve is opened and closed exactly once within each block. Each block includes from two to twenty revolutions of the crankshaft. The fuel valve is opened over a crankshaft angle (α) of more than 360° within one block in at least one operating state. A control device is provided for controlling the fuel valve. A quasi-steady state of the two stroke engine is a state in which the throttle element is adjusted by less than 10% of the maximum adjustment of the throttle element over a crankshaft angle (α) of 360°.

Methods and systems are provided for balancing injector fueling. In one example, a method includes learning portions of a transfer function shape by firing a plurality of injectors at PWs of a set of PWs following a reference injection.

A method for determining a switching point of a solenoid valve. A solenoid coil is energized to raise a solenoid armature to unblock a flow opening. For a signal profile characteristic of a current profile in the solenoid coil, multiple periods each different from one another and each having the same predefined temporal length are determined. Within each period, a minimal and a maximal value of the signal profile and associated points in time are ascertained and a product of a difference between the maximal and minimal value and a difference between the associated points in time are ascertained. On the basis of the points in time of the minimal and maximal value of that period, which corresponds to a maximal value of the product, the switching point is determined.

A method for ascertaining the movement of an armature of an electric intake valve, an electrical variable of the electric intake valve being controlled to predefined values with the aid of a two-position controller, a characteristic point in time of the movement of the armature being ascertained based on the switching behavior of the two-position controller.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes determining a fuel injector error shape and applying a fueling correction to all injectors based on the fuel injector error shape.

A method for controlling a fuel injector includes applying a spill valve current, applying a control valve current, the control and spill valves including components in electrical communication with each other, and detecting a timing at which the spill valve returns to an open position based on induced spill valve current. The method includes detecting a timing at which the control valve returns to a resting position based on induced control valve current, the induced spill valve current and the induced control valve current being included in respective freewheeling currents that at least partially overlap each other, adjusting a spill valve current that is applied during an injection, based on the detected spill valve return timing, and adjusting a control valve current that is applied during the injection, based on the detected control valve return timing.

A fuel injection method includes applying a first method current to close a spill valve according to a first method, applying a control valve current to open a control valve, and discontinuing the application of the control valve current to thereby cause the control valve to close. The method also includes applying a second method current to maintain the spill valve closed according to a second method and detecting a timing of a closing of the control valve while applying the second method current according to the second method, the second method being different than the first method.

Provided is a fuel injection control device capable of reducing variations in injection amounts of a plurality of fuel injection valves. Thus, the fuel injection control device of the present invention includes a control unit that controls voltages applied to coils of a plurality of fuel injection valves, the coils being adapted for energization. The control unit performs control such that the voltage being applied to the coil is cut off. The control unit changes a timing at which the cutoff of the voltage to the coil of at least one fuel injection valve is started or a timing at which the cutoff of the voltage to the coil of at least one fuel injection valve is ended, based on a valve closing time until closing of the fuel injection valve is completed or a valve opening time until opening of the fuel injection valve is completed.