A direct fuel injection engine including an ignition plug and a fuel injection valve arranged to be capable of injecting a fuel directly in a cylinder is controlled. The engine has a predetermined operation region in which an excess air ratio of an air-fuel mixture is set in a vicinity of 2. In a first region on a low load side of the predetermined operation region, a homogenous air-fuel mixture having the excess air ratio at a first predetermined value in the vicinity of 2 is formed upon combustion, and in a second region on a load side higher than the first region, a stratified air-fuel mixture having the excess air ratio at a second predetermined value in the vicinity of 2 is formed upon combustion.

A pressurized fuel injection system for an engine includes a pressure sensor in a low pressure rail, an electronic pressure regulator valve in flow communication with and downstream from the low pressure rail and in flow communication with and upstream from a fuel supply, and a controller configured to receive a pressure signal from the pressure sensor and to control the electronic pressure regulator valve in response to the pressure signal to maintain a target pressure in the low pressure rail.

A pressurized fuel injection system for an engine includes a pressure sensor in a low pressure rail, an electronic pressure regulator valve in flow communication with and downstream from the low pressure rail and in flow communication with and upstream from a fuel supply, and a controller configured to receive a pressure signal from the pressure sensor and to control the electronic pressure regulator valve in response to the pressure signal to maintain a target pressure in the low pressure rail.

A fuel system for an internal combustion engine includes a fuel control system having a fueling control unit structured to determine a test point on a tip wear-sensitive region of a fuel injector delivery curve, and store measurements of pressure drops in a pressurized fuel reservoir caused by injections of fuel at the test point. The fueling control unit is further structured to produce an injector health signal based on the stored measurements of pressure drop. Related methodology and control logic for calculation of wear parameters for injection signal duration electronic trimming and prognostic health determinations are also disclosed.

A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

The purpose of the present invention is to detect variations between the quantities of fuel injected into cylinders by fuel injection devices and correct the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor. A drive device for fuel injection devices according to the present invention performs control wherein movable valves are driven so that predetermined quantities of fuel are injected by applying, for the duration of a set energization time, a current that will reach an energization current to solenoids of a plurality of fuel injection devices which open/close fuel flow paths. The drive device is characterized in that the set energization time or energization current is corrected on the basis of a pressure detection value from a pressure sensor that is attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices.

The purpose of the present invention is to detect variations between the quantities of fuel injected into cylinders by fuel injection devices and correct the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor. A drive device for fuel injection devices according to the present invention performs control wherein movable valves are driven so that predetermined quantities of fuel are injected by applying, for the duration of a set energization time, a current that will reach an energization current to solenoids of a plurality of fuel injection devices which open/close fuel flow paths. The drive device is characterized in that the set energization time or energization current is corrected on the basis of a pressure detection value from a pressure sensor that is attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices.

An injection control device controls a solenoid in a fuel injection valve. The injection control device includes a transistor on an upstream side of a first power supply path to the solenoid and a transistor on an upstream side of a second power supply path to the solenoid. The injection control device has another transistor with a body diode arranged in parallel at a position on the first power supply path between the first transistor and an upstream terminal of the solenoid. The injection control device also includes a transistor on the downstream side of the first and second power supply paths. A drive controller in the injection control device drives the solenoid to an open position by switching ON the transistor on the downstream side and the transistor on the upstream side of the first power supply path or the transistor on the upstream side of the second power supply path.

A fuel injection control device for an internal combustion engine includes an electronic control unit configured to execute division processing for learning for dividing a requested injection amount into an injection amount of partial lift injection of an in-cylinder injection valve and a port injection amount of injection of a port injection valve, detect, on the basis of at least one of a terminal electric potential of a coil and a current flowing through the coil, an inflection point of a change in induced electromotive force of the coil in time attributable to a decline in a relative speed of a mover with respect to the coil, and correct the energization processing at a time when the partial lift injection is executed based on a timing of the detection of the inflection point.

A fuel system for an internal combustion engine includes a fuel control system having a fueling control unit structured to determine a test point on a tip wear-sensitive region of a fuel injector delivery curve, and store measurements of pressure drops in a pressurized fuel reservoir caused by injections of fuel at the test point. The fueling control unit is further structured to produce an injector health signal based on the stored measurements of pressure drop. Related methodology and control logic for calculation of wear parameters for injection signal duration electronic trimming and prognostic health determinations are also disclosed.