A method and device for controlling a four-stroke internal combustion engine, including a step of producing a reconstituted crankshaft signal having an electrical signal extending over two crankshaft revolutions in the nominal direction of rotation of the engine, the electrical signal including: a single main pulse, having a predetermined first duration, corresponding to the passing of a predetermined reference tooth of the toothed wheel associated with the crankshaft of the engine; a plurality of secondary pulses, each having a predetermined second duration, each corresponding to the passing of a tooth of the toothed wheel associated with the crankshaft of the engine; the predetermined first duration being greater than the predetermined second duration.

When a rotational speed of an engine is higher than a predetermined rotational speed, a low-pressure fuel injection valve is controlled through the use of a fuel injection time based on an estimated fuel pressure in a low pressure supply pipe and a target fuel injection amount. When the rotational speed of the engine is equal to or lower than the predetermined rotational speed, the low-pressure fuel injection valve is controlled through the use of a fuel injection time based on a detected fuel pressure input from the fuel pressure sensor from the issuance of a command to activate energization of a solenoid to the start of energization of the solenoid and a target fuel injection amount.

A secondary fuel injection system determines (precisely) a maximum amount of secondary fuel that can be injected into a cylinder during a cycle based upon the rotational speed (RPM) of the engine. A primary fuel injection pulse width of the prior cycle and is used to determine how much heat energy was requested by an engine control module based upon the duration of the injection pulse. Secondary fuel is injected into the intake port of the cylinder after the exhaust valve closes in an amount that is calculated based upon the maximum that can be injected during the allowed calculated time of crankshaft rotation and the amount of heat energy requested in the prior cycle and to include the amount of primary fuel that is then injected into the cylinder is being reduced based upon the amount of heat energy provided by the secondary fuel that was previously injected.

A method of adaptively sampling data to determine the start of injection in a solenoid actuated valve of a fluid injector includes, in an operating cycle or portion thereof of the valve, sampling the signal of current through a solenoid of the valve at sampling points having a pre-defined interval therebetween. At each sampling point, determining the value of the first derivative of current and detecting the sampling point at which the first derivative achieves a maximum as the start of injection. Values of the first derivative of the sampling points immediately preceding and immediately following the start of injection are determined. In a subsequent operating cycle, synchronisation of sampling is altered to shift sampling times depending on the values of the first derivative of the sampling points immediately preceding and immediately following the start of injection.

A control system comprising a variable valve timing mechanism (B) able to set a closing timing of an intake valve (7), a fuel injector (13) for feeding fuel to a combustion chamber (5), an intake air amount detector (17) for detecting an amount of intake air fed to an intake passage from the outside air, and a pressure sensor (16) for detecting the pressure in the intake passage downstream of a throttle valve (16). When air in the combustion chamber (5) is blown back to the intake passage when injection of fuel is restarted after the fuel injection is stopped at the time of deceleration operation, the basis for calculation of the fuel injection amount in the initial cycle when fuel injection is restarted is switched from the amount of intake air detected by the intake air amount detector (17) to the pressure in the intake passage detected by the pressure sensor (18).

The system, according to one embodiment of the present invention, comprises a stationary coil linear motor to drive a valve with a stem comprising a ferromagnetic property. The linear motor moves the valve in response to control governed by an electronic valve control computer. The valve is movable between a closed position at a selectable rate of both acceleration and speed for a selectable distance (“lift”) to a second selectable open position, including all position variations between the fully open and fully closed states. Valve position, velocity and acceleration can be varied both during a valve stroke and from one stroke to the next, as controlled by the logic programmed on a non-transitive memory of the electronic valve control computer.

Methods and systems are provided for injecting and combusting an amount of gaseous fuel during an exhaust stroke of a cylinder combustion event in order to reduce turbo lag and reduce a duration of time required for an exhaust catalyst to light-off during transient events. In one example, when an increase in torque demand is greater than a threshold, a first amount of gaseous fuel may be combusted during a compression stroke of a cylinder combustion event and a second amount of gaseous fuel may be combusted during an exhaust stroke of the combustion event. The second amount may be adjusted based on the increase in torque demand.

Methods and systems are provided for injecting and combusting an amount of gaseous fuel during an exhaust stroke of a cylinder combustion event in order to reduce turbo lag and reduce a duration of time required for an exhaust catalyst to light-off during transient events. In one example, when an increase in torque demand is greater than a threshold, a first amount of gaseous fuel may be combusted during a compression stroke of a cylinder combustion event and a second amount of gaseous fuel may be combusted during an exhaust stroke of the combustion event. The second amount may be adjusted based on the increase in torque demand.

Systems and methods for improving fuel injection of an engine that includes a cylinder receiving fuel from two different fuel injectors is disclosed. In one example, fuel is supplied to port fuel injectors and direct fuel injectors via a same high pressure fuel pump, and high pressure port fuel injection is activated at times where direct fuel injection would supply less fuel than is desired or an inconsistent amount of fuel.

A method for detecting variations between the quantities of fuel injected into cylinders by fuel injection devices and correcting the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor includes a drive device for fuel injection 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.