A method for heating an exhaust gas aftertreatment component in an exhaust system of an internal combustion engine. At the combustion chamber, a fuel injector for injecting a fuel into the combustion chamber and a spark plug for igniting a flammable fuel-air mixture are arranged. The internal combustion engine has a valve lift curve switching mechanism, which allows for a shift and/or change of the opening times of the exhaust valve. The method includes: intake of fresh air into the combustion chamber, injection of a fuel into the combustion chamber, ignition of an ignitable fuel-air mixture in the combustion chamber when the piston is in a range of 10° KW to 30° KW after the upper ignition dead point, and opening of the exhaust valve when the piston is in a range of 55° KW to 95° KW after the upper ignition dead point.

Methods and systems are provided for a vehicle engine having a pre-chamber ignition system. In one example, a method may include adjusting one or more of an air injection amount and a fuel injection amount to a pre-chamber of an engine based on an air injection offset and a fuel injection offset learned while discontinuing fueling to cylinders of the engine and reducing air flow through the engine. In this way, air and fuel may be more accurately provided to the pre-chamber, thereby decreasing an occurrence of pre-chamber misfire.

A method, for an internal combustion engine including an intake camshaft equipped with a variable intake valve timing device including an intake timing actuator and an exhaust camshaft equipped with a variable exhaust valve timing device including an exhaust timing actuator, of detecting inverted connection of the intake timing actuator with the exhaust timing actuator, including: measuring the angular position of the intake camshaft and the angular position of the exhaust camshaft; commanding one of the two timing actuators according to a setpoint and keeping the other of the two timing actuators immobile; measuring the angular positions of the intake camshaft and of the exhaust camshaft; and comparing: if the angular position of the camshaft corresponding to the timing actuator that's been commanded has not been modified, and if the angular position of the camshaft corresponding to the immobile timing actuator has been modified, inverted connection can be diagnosed.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.

A method detects a fault, in particular coking, in the intake tract of an internal combustion engine with direct fuel injection, a throttle valve, and a variable intake valve lift controller. The method has the steps of a) carrying out a first quantity deviation test, by which a first air ratio value is ascertained that is formed from a lambda value, which is measured during the first quantity deviation test, and a desired lambda value of the fuel combustion in the fuel chambers of the internal combustion engine, wherein in the first quantity deviation test, a load control is carried out by the variable intake valve lift controller; b) carrying out a second quantity deviation test, by which a second air ratio value is ascertained that is formed from a lambda value, which is measured during the second quantity deviation test, and a desired lambda value of the fuel combustion in the fuel chambers of the internal combustion engine, wherein in the second quantity deviation test, a load control is carried out by the throttle valve; and lastly c) determining a comparison result from the first air ratio value and the second air ratio value, the presence of a fault in the intake tract of the internal combustion engine being detectable using the comparison result.

An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation condition.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A method for advancing valve actuation during low load or idle diesel engine conditions to promote aftertreatment heat up comprises switching a cam phaser from a nominal lift position to an advance lift position to open an affiliated valve before nominal. Valve lift is actuated via the cam phaser. The valve is lowered towards nominal closure, and valve closure is interrupted by actuating a latch phaser. Valve closure is extended beyond nominal valve closure.

The invention relates to controlling engine braking of an internal combustion engine wherein the method includes setting the engine in an engine braking mode comprising i) interrupting fuel supply to a first cylinder, ii) restricting the flow of gas through an exhaust duct using an adjustable flow restricting member, and iii) controlling inlet and exhaust valves of the first cylinder in a compression-release mode comprising controlling the valves to compress gas in a combustion chamber when the piston moves towards the top dead center position (TDC) and release compressed gas into the exhaust duct when the piston is near the TDC. The method includes, prior to ii and iii: reducing a total gas mass flow rate through the engine by controlling, for at least one of valve, reducing a valve lift and/or adjusting a timing of a valve opening or closing so as to reduce the gas mass flow rate through the cylinder.