An apparatus for in-line re-calibration of engine load signal, the apparatus having a housing and a first connector disposed on the housing, adapted to plug into an electrical connection socket of an automotive air intake sensor. A second connector is disposed on the housing, adapted to mimic the electrical connection socket of the automotive air intake sensor. An electronic circuit is disposed in the housing, the electronic circuit adapted to re-calibrate signals from the automotive air intake sensor and deliver the re-calibrated signals the to the second connector. The housing is adapted to plug in-line directly into the electrical connection socket of the automotive air intake sensor, whereby the corresponding electrical wiring connector to an engine control unit plugs directly into the second connector of the housing, completing the inline connection.

In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount determined for mixed fuel based on fuel injection amount characteristics is increased/decreased when a load is kept constant and the output air/fuel ratio is estimated to correct the fuel injection amount by the estimated air/fuel ratio, while a switch (knob) is installed to be manipulated by the operator to switch the fuel injection amount characteristics.

A method and test device for recognizing detecting whether a mass air flow meter of intake air of an internal combustion engine is defective is provided. In the method and device, a test procedure is executed using a pilot controller while a mixture controller that is used in non-test engine operation is deactivated. The pilot controller for the mixture of fuel and air in the respective cylinders outputs control values which, during normal operation of the internal combustion engine via the mixture control, are varied on the basis of a mixture deviation of the current mixture from a stoichiometric mixture. The engine is set to one or more different idling speeds and at each respective idling speed the mixture deviation is detected. If the detected mixture deviation(s) (i'lA.) satisfy a predetermined criteria thresholds, the air flow meter is identified as defective.

Control of airflow in a uniflow-scavenged, two-stroke cycle, opposed-piston engine during transient operation includes monitoring at least one operating parameter of the engine to recognize a transition to a transient state of engine operation. If a transient state of operation is detected, fuel injection and airflow into to the cylinders of the engine are controlled to optimize combustion and limit emissions. Airflow into cylinders of the engine may be controlled by increasing a scavenging ratio of the engine or by increasing a trapping efficiency of the engine.

A method for determining an air mass air in a cylinder of an internal combustion engine is disclosed. A first filling equivalent is determined during a compression phase of the cylinder, wherein the first filling equivalent corresponds to a first average pressure difference in a first angle range of a crank angle in the compression phase. A second filling equivalent is determined during an expansion phase of the cylinder, wherein the second filling equivalent corresponds to a second average pressure difference in a second angle range of the crank angle of the expansion phase. A differential filling equivalent is calculated by subtracting the first filling equivalent from the second filling equivalent. The air mass in the cylinder is determined based on the differential filling equivalent.

A controller for an internal combustion engine is configured to control the fuel injection valve so that the fuel injection valve selectively performs partial lift injection, which does not open a valve member at a fully open position, and full lift injection, which opens the valve member at the fully open position. The internal combustion engine includes the fuel injection valve and a fuel supply system. The controller includes an energizing time setting unit, a fuel pressure calculation unit, and a smoothening process unit. The energizing time setting unit is configured to set an energizing time for the full lift injection based on graded fuel pressure calculated by the smoothening process unit and set an energizing time for the partial lift injection based on fuel pressure calculated by the fuel pressure calculation unit.

A method for calculating Atkinson cycle intake flowrate of an internal combustion engine includes determining an intake stopping point and an engine crank angle corresponding to a piston position of the internal combustion engine at the intake stopping point; calculating mass and partial pressure of an exhaust gas and a fresh gas within a cylinder from the engine crank angle; obtaining a mass ratio of a quantity of gas pushed out of the cylinder by a piston to a total quantity of gas within the cylinder at the intake stopping point during a period of time starting from the intake stopping point until intake valve closure; and calculating intake flowrate of the fresh gas within the cylinder at the intake valve closure from the mass ratio obtained. Also disclosed is a system for calculating Atkinson cycle intake flowrate of an internal combustion engine.

An engine controller is configured to perform fuel cut-off, which temporarily stops fuel injection, calculate an in-cylinder air amount, which is an amount of air used for combustion in a cylinder, and control an engine based on the in-cylinder air amount. The engine controller includes a residual air amount calculation unit configured to calculate a residual air amount that is an amount of air in the cylinder remaining from a previous cycle during the fuel cut-off so that the residual air amount increases as the number of cycles of intake-exhaust actions in the cylinder increases during the fuel cut-off.

Methods, devices, estimators, controllers and algorithms are described for estimating working chamber air charge during engine operations. The described approaches and devices are well suited for use in dynamic firing level modulation controlled engines. Manifold pressure is estimated for a time corresponding to an induction event associated with a selected working cycle. The manifold pressure estimate accounts for impacts from one or more intervening potential induction events that will occur between the time that the manifold pressure is estimated and the time that the induction event associated with the selected working cycle occurs. The estimated manifold pressure is used in the estimation of the air charge for the selected working cycle. The described approach may be used to individually calculate the air charge for each induction event at any time that the engine is operating in a mode that can benefit from the individual cylinder air charge estimations.

The present invention relates to a method for adapting engine control of a gas engine in a vehicle. The method comprises determining, during operation of the gas engine, the specific gas constant of a fuel gas for the gas engine. The method further comprises determining the stoichiometric air fuel ratio of the fuel gas for the gas engine. The control of the gas engine is adapted based on the determined specific gas constant and the determined stoichiometric air fuel ratio. The present invention also relates to a system for adapting engine control of a gas engine in a vehicle, to a vehicle, and to a computer program product.