A dual fuel engine system, such as for diesel and natural gas operation, includes a control system having an electronic control unit structured to vary a stored control valve for a fuel delivery parameter, responsive to engine power output. The engine power output can be determined by in-cylinder pressure monitoring during a liquid fuel mode. The stored control value can be a dynamically updated value in an engine fueling map.

An engine assembly includes an engine, a compressor, a turbine and a waste gate valve. A controller has a processor and a tangible, non-transitory memory on which is recorded instructions for executing a method of air path control based on an air path model. The controller is configured to determine a turbine power (P.sub.t) as a function of a first factor (x.sub.1) and a second factor (x.sub.2). A compressor power (P.sub.c) is determined as a function of a third factor (y.sub.1) and a fourth factor (y.sub.2). The controller is configured to control at least one of an intake throttle pressure (p.sub.th) and an intake manifold pressure (p.sub.i) by varying at least one of the first through fourth factors (x.sub.1, x.sub.2, y.sub.1, y.sub.2). The engine output is controlled based on at least one of the intake throttle and manifold pressures.

A control device of an internal combustion engine includes an estimating means adapted to estimate an amount of a mixture of fuel and oil dispersing according to a movement of a piston within a cylinder; and a limiting means adapted to limit an upper limit torque (UT) of an internal combustion engine according to the estimated amount of the mixture.

Methods and systems are provided for reducing fouling of a spark plug in a cylinder of a variable displacement engine configured to propel a vehicle. In one example, a method includes in response to deactivation of a cylinder or cylinders of the engine, providing spark to the cylinder or cylinders at a predefined position of a piston or pistons coupled to the cylinder or cylinders, respectively, where the predefined position comprises the piston or pistons being within a threshold of a bottom dead center position. In this way, spark plug fouling may be reduced or eliminated during conditions of cylinder deactivation.

A method of controlling a Free Piston Mover, the method comprising the steps of: generating a Control Parameter Set for closed loop control of a Target Control Variable, this set comprising a Target Control Variable Function together with one or more of: a Stroke Threshold Function; a Feed Forward Current Function; a Feedback Terms Function; Control Parameter Set Transition Conditions; transmitting the Control Parameter Set to an In-Stroke Controller in advance of the start of a Stroke to be controlled; modifying one or more of the constituents of the Control Parameter Set for any Future Stroke of the Free Piston Mover using a Future-Stroke Controller; and transmitting the modified Control Parameter Set to the In-Stroke Controller for the control of any Future Stroke.

A control apparatus for an internal combustion engine is configured, during a slightly stratified-charge lean-burn operation, to: calculate a basic total fuel injection amount based on a required torque; calculate a compression stroke injection amount based on an ignition delay index value; calculate, as a basic main injection amount, a value obtained by subtracting a compression stroke injection amount from the basic total fuel injection amount; calculate, based on an output value of an in-cylinder pressure sensor, an actual specified combustion index value that represents a main combustion speed or a combustion fluctuation rate; calculate a main injection correction term based on a result of a comparison between a target specified combustion index value or a tolerable specified combustion index value, and the actual specified combustion index value; and calculate a main injection amount by adding the main injection correction term to the basic main injection amount.

Disclosed herein are techniques for implementing vehicle ECU reprograming, so the ECU programming, which plays a large role in vehicle performance characteristics, is tailored to current operational requirements, which may be different than the operational characteristics selected by the manufacturer when initially programming the vehicle ECU (or ECUs) with specific instruction sets, such as fuel maps. In one embodiment, a controller monitors the current operational characteristics of the vehicle, determines the current ECU programming, and determines if a different programming set would better suited to the current operating conditions. In the event that the current programming set should be replaced, the controller implements the ECU reprogramming. In a related embodiment, users are enabled to specify the ECU programming to change, such as changing speed limiter settings.

A method for operating an internal combustion engine is presented in which a noise characteristic value, which is representative of a measurement of a noise of the measurement signal of a respective exhaust gas probe, is determined as a function of a profile of the measurement signal of the respective exhaust gas probe. A pressure characteristic value, which is assigned to a respective cylinder, is determined as a function of a profile of a measurement signal of a crankshaft angle sensor and a profile of a pressure measurement signal of a cylinder pressure sensor. Respective actuation signals for actuating respective injection valves are adapted as a function of the pressure characteristic value and the noise characteristic value assigned to the respective cylinder, for the purpose of approximating an air/fuel ratio in the individual cylinders.

A method for regulating the rail pressure in an injection system of a motor vehicle is described. For the purpose of regulating the rail pressure, a high-pressure pump, which is provided with a digital inlet valve, is actuated, wherein the digital inlet valve is activated such that it is matched to the delivery and suction phase physically present. In this way, it is possible for pressure regulation to be achieved by way of a digital valve even for transmission ratios at which the pump does not have exactly a multiple of delivery and suction phases during two engine cycles.

A method for implementation with the operation of an internal combustion engine, having an ignition plug, which is arranged on a combustion chamber of a cylinder of the internal combustion engine, wherein: in a first step, a cylinder pressure at the ignition time at the combustion chamber is detected, as well as a breakdown voltage at the ignition plug; and in a second step, a current electrode distance of the ignition electrodes, representing a current ignition electrode wear state, is determined based on the detected cylinder pressure, the detected breakdown voltage and a constant of proportionality.