The present invention relates to a method for supplying fuel for a motor of a vehicle by a fuel supply system comprising: a first tank for containing a first fuel; supply means for supplying fuel to the motor; a supply line, for allowing said first fuel to pass from said first tank to said supply means; a return line, for allowing fuel to pass from said supply means to said first tank; a recirculating line, connected with said supply line and said return line, for allowing fuel to pass from said return line to said supply line; and valve means, configured to selectively direct fuel from said return line to said supply line by said recirculating line, or to said first tank; wherein said method comprises the steps of controlling the speed vehicle; controlling the vehicle motor load; defining a first threshold value of the vehicle speed; defining a second threshold value for the vehicle motor load; letting said first fuel passing from said first tank to said supply means through said supply line, and from said supply means to said first tank through said return line, preventing passage of fuel along said recirculating line, when the vehicle speed is lower than said first threshold value and/or motor load is lower than said second threshold value; or making said first fuel passing from said first tank to said supply means through said supply line and then through a closed circuit comprising a part of said return line, said recirculating line and a portion of said supply line, permitting passage of said first fuel through said recirculating line, so that said first fuel arrives again within said supply means, when the vehicle speed is higher than said first threshold value and motor load is higher than said second threshold value, so as to prevent an excessive increase within said first tank caused by inlet within the first tank of the first fuel warm arriving from said supply means.

Methods and systems for operating an engine with different fuels having different cetane levels are described. In one example, start of fuel injection timing for engine cylinders may be adjusted responsive to engine deceleration or combustion phase during engine cranking. The start of fuel injection timing may be retarded for higher cetane fuels and advanced for lower cetane fuels.

A method for controlling an engine system having a supercharger and a turbocharger includes: an accelerator-pedal-opening-degree determination operation of determining whether an opening degree of an accelerator pedal detected after an engine starts is a first reference value or more; a first coolant temperature determination operation of determining whether, when the opening degree of the accelerator pedal is less than the first reference value, a detected temperature of a coolant is a second reference value or more; a second coolant temperature determination operation of determining whether the temperature of the coolant is the second reference value or more and is within a temperature threshold; and a boosting operation of calculating boosting contribution rates of the supercharger and the turbocharger, respectively, when the determined temperature of the coolant is within the temperature threshold and driving the supercharger and the turbocharger using the calculated boosting contribution rates.

A control device for an internal combustion engine provided with a combustion control part sequentially injecting at least a primary auxiliary fuel, secondary auxiliary fuel, and main fuel from a fuel injector in predetermined operating regions, causing compressive ignition sequentially from a premix containing the primary auxiliary fuel after injection of the main fuel, and causing compressive ignition of a premix containing the main fuel using heat generated when causing compressive ignition of a premix containing the secondary auxiliary fuel, the combustion control part setting a target injection amount and target injection timing of the primary auxiliary fuel so that a peak value and a slant of a heat generation rate pattern formed by a premix containing the primary auxiliary fuel is smaller than peak values and slants of heat generation rate patterns formed by the premixes containing the secondary auxiliary fuel and the main fuel.

A control apparatus for an internal combustion engine is provided. The control apparatus includes a temperature sensor and an electronic control unit. The temperature sensor is configured to detect the temperature of an exhaust gas control apparatus. The electronic control unit is configured to: estimate a sulfuric compound accumulation amount on the exhaust gas control apparatus; and when a specific condition in which the sulfuric compound accumulation amount is equal to or larger than a predetermined accumulation amount and the temperature of the exhaust gas control apparatus is equal to or higher than a predetermined temperature or more is satisfied, control an intake air amount adjuster such that an intake air amount when the specific condition is satisfied is increased as compared to the intake air amount when the specific condition is not satisfied in the same operation state.

Disclosed herein are techniques for implementing vehicle ECU reprogramming, 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.

Methods and systems for operating an engine with different fuels having different cetane levels are described. In one example, start of fuel injection timing for engine cylinders may be adjusted responsive to engine deceleration or combustion phase during engine cranking. The start of fuel injection timing may be retarded for higher cetane fuels and advanced for lower cetane fuels.

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.

An internal combustion engine having a plurality of cylinders comprises a variable compression ratio mechanism A able to change a mechanical compression ratio. The control device comprises a compression ratio detector for detecting a mechanical compression ratio based on a value of the relative position parameter representing a relative positional relationship between the cylinder block 2 and a piston 4, and a compression ratio controller for feedback controlling the mechanical compression ratio so that the mechanical compression ratio becomes a target mechanical compression ratio. In feedback controlling the variable compression ratio mechanism, the compression ratio controller does not use the mechanical compression ratio detected by the compression ratio detector when a crank angle is in a predetermined crank angle range including a time period where the cylinder pressure is equal to or greater than a preset predetermined pressure at least at one cylinder among the plurality of cylinders.

A process and a system for preventing pre-ignition in an internal combustion engine (ICE) includes detecting an ionization level of a combusted gas from a cylinder of the ICE during gas exchange and for a given combustion cycle i. When the ionization level is greater than a reference ionization level a pre-ignition countermeasure prior to and/or during an immediate subsequent combustion cycle i+1 is executed. The ionization sensor may be part of a spark initiating device of the ICE or be a separate ionization sensor.