Each time clogging of a filter (5) of an air cleaner is determined on the basis of intake negative pressure of an engine (2), and the air filter (5) is cleaned, an accumulated value of operating time of the engine (2) from previous cleaning until clogging is determined is taken as a cleaning interval (S), and sequentially measured. A plurality of stages are previously set by classifying a minimum value and a maximum value of the cleaning interval (S), and the measured cleaning interval (S) is added to the stage to which the measured cleaning interval (S) is to belong, among the stages. A histogram in which an axis of abscissas is taken as the stage, an axis of ordinates is taken as frequency of the cleaning interval (S) is constructed, and an approximate straight line (L2) illustrated by a solid line is obtained by approximating a characteristic line (L1) of the histogram illustrated by a dotted line to a straight line. A characteristic of the histogram is changed as the deterioration of the air filter (5) progresses, and when a slope of the approximate straight line (L2) based on the characteristic gradually decreases from right-upward slop illustrated by a thin line, exceeds (ΔY/ΔX=0) equivalent to the horizontal, deterioration of the air filter is determined.

Various embodiments include a method for detecting deviations occurring in the valve drive of an internal combustion engine comprising: measuring dynamic pressure oscillations of intake air in an air intake tract of respective internal combustion engine during operation; calculating an inlet valve stroke phase difference and/or an outlet valve stroke phase difference based on the measured dynamic pressure oscillation; calculating a valve stroke phase deviation value with respect to a valve stroke phase reference value based on the calculated phase difference; and calculating a first valve drive deviation value based on the valve stroke phase deviation value.

A method and system for operating a vehicle that includes feedback of operating status of an engine starting system is described. In one example, the method inhibits automatic engine pull-down in response to feedback from an engine starting system that does not meet expectations. The system and method may provide diagnostics for the engine starting system.

A fuel injection control method of injecting fuel to a combustion chamber through an injector, the method may include performing, by a controller electrically-connected to the injector, a main injection configured of controlling the injector to inject the fuel in a target injection fuel amount; and performing, by the controller, a pre-injection configured of driving the injector to inject the fuel in advance, before the performing of the main injection with a predetermined idle time interposed therebetween, wherein the performing of the pre-injection is configured of magnetizing an injector coil of the injector by applying a current to the injector during a predetermined pre-injection time, in which a flow rate of the fuel is prevented from being generated by the pre-injection.

A method for operating a vehicle that may be automatically stopped and started is described. In one example, the method includes inhibiting automatic engine stopping in response to a temperature of an emissions device exceeding a threshold temperature. In addition, additional actions may be taken to reduce the temperature of the emissions device when automatic engine stopping is inhibited.

Provided is a technology of accurately classifying abnormality in response characteristics of an air-fuel ratio sensors into six deterioration modes. In order to solve the above problems, the present disclosure provides a control device including a microprocessor that detects a response delay of an air-fuel ratio sensor attached to an internal combustion engine, in which the microprocessor includes a target air-fuel ratio change unit configured to change a target air-fuel ratio between lean and rich, and a response delay detection unit configured to detect a respond delay of the air-fuel ratio sensor that occurs in a real air-fuel ratio sensor signal output from the air-fuel ratio sensor when the target air-fuel ratio is changed between the lean and the rich by the target air-fuel ratio change unit.

There is provided with an engine control device that can reduce the time it takes to start the monitoring of an output of an engine. The engine control device comprises a monitor unit configured to monitor an output of an engine when engine speed is a threshold or more, and a control unit configured to control the engine based on a result of the monitor unit, wherein the monitor unit includes an output determination unit that determines whether the output of the engine is excessive, and a change unit that changes in accordance with a warm-up state of the engine, the threshold.

A system includes a controller having a control signal generation unit that provides control signals to actuate one or more valve actuators of an engine to a desired position, and control signals to modify one or more operational parameters and an operational mode of the engine. A parameter signal process unit receives parameter signals corresponding to at least one operational parameter of the engine, and at least one sensor coupled to the engine. At least one sensor corresponds to a position of a valve. A failure detection unit generates at least one fault code corresponding to one or more failure modes. A failure mode isolation unit isolates a failure mode from the one or more failure modes in response to modifying the operational parameters or the operational mode, causing actuation of the valves to a desired position, or receiving the parameter signals and the sensor.

[Problem to be Solved]

To provide a driving control device for a fuel pump that can properly control the fuel pump such that an operation state is maintained with a simple configuration without requiring a storage capacity for storing a 3D map and a high processing ability for map calculation.

[Solution]

A driving control device for a fuel pump is characterized by including a valve-opening-rate calculating unit 33 that calculates an injector valve opening rate, which is an injection time of an injector per unit time and a driving control unit 34 that sets a voltage duty ratio of a driving voltage that should be applied to the fuel pump that supplies fuel in a fuel tank to a fuel pipe communicating with the injector, in which the driving control unit 34 sets, as a voltage duty ratio of the driving voltage that should be applied to the fuel pump, a value proportional to the injector valve opening rate calculated by the valve-opening-rate calculating unit.

A control device of a general-purpose engine which can continue operation of a working machine even when an operation management unit of the working machine has failed. The control device includes an engine control unit that controls the general-purpose engine based on a command from the operation management unit managing an operating state of the working machine, a communication interface for communicating with an external device; a management program acquisition unit that acquires a management program that is used by the operation management unit to manage the operating state, from the external device through the communication interface and stores the acquired management program in a storage medium, and an operation management substitute unit that manages the operating state of the working machine in place of the operation management unit in accordance with the management program when a failure of operation management unit is detected.