Systems and methods for starting and operating a direct injection engine are described. In one example, the air and fuel are injected into a pre-chamber of a cylinder of an engine while the engine is not rotating. The air and fuel are combusted in the pre-chamber to improve ignition of an air and fuel mixture in the cylinder.

Systems and methods for starting and operating a direct injection engine are described. In one example, the air and fuel are injected into a pre-chamber of a cylinder of an engine while the engine is not rotating. The air and fuel are combusted in the pre-chamber to improve ignition of an air and fuel mixture in the cylinder.

The present invention relates to a device and a method for controlling the start of an internal combustion engine, wherein the internal combustion engine is equipped with an ignition device comprising a fuel-fed prechamber to ignite an air-fuel mixture in a main combustion chamber. In order to reduce the emissions of the internal combustion engine during engine start a prechamber heating operations is performed by injecting a predetermined amount of fuel into the prechamber and igniting an air-fuel-mixture therein, while the main fuel injector is deactivated during at least a first engine cycle after engine start request.

Methods and systems are provided for adjusting multiplexed ignition signals in an engine system based on engine operating conditions, each cylinder of the engine system including a main chamber spark plug and a pre-chamber system. In one example, a method may include multiplexing spark signals to a first spark plug, a second spark plug, a third spark plug, and a fourth spark plug, the first spark plug coupled to a pre-chamber of a first cylinder, the second spark plug coupled to a pre-chamber of a second cylinder, the third spark plug coupled to a main chamber of the first cylinder, and the fourth spark plug coupled to the main chamber of the second cylinder. In this way, one ignition coil may be used to actuate two different spark plugs coupled to separate cylinders.

A fuel injection system for a spark-ignition internal combustion engine having a number of cylinders, where a plurality of respective main combustion chambers are defined; a number of first injectors and spark plugs coupled to the cylinders; a number of combustion pre-chambers, each obtained in the area of a respective spark plug; a number of extraction ducts, which originate from a respective cylinder to extract the gas mixture present inside the respective main combustion chamber; a reserve, where the gases extracted by the extraction ducts are mixed with the quantity of fuel needed to obtain a combustion under stoichiometric conditions inside the combustion pre-chambers; and a number of second injectors, each coupled to a respective combustion pre-chamber, into which it injects the gas-and-fuel mixture coming from the reserve.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber system. In one example, a method includes flowing gases from a pre-chamber to a cylinder of an engine prior to fueling the cylinder during a combustion cycle, adjusting a composition of the gases by adjusting at least one of an air injection amount to the pre-chamber and a fuel injection amount to the pre-chamber, and igniting an air-fuel mixture in the cylinder via a pre-chamber ignition event, the air-fuel mixture in the cylinder including the gas from the pre-chamber. In this way, combustion qualities in the cylinder may be adjusted in order to increase a performance and/or an efficiency of the cylinder.

Methods and systems are provided for combusting an air-fuel mixture in a pre-chamber of a cylinder during an exhaust stroke of the cylinder responsive to fouling of the pre-chamber. In one example, a method may include injecting air into the pre-chamber during the exhaust stroke, injecting fuel into the pre-chamber during the exhaust stroke, and actuating a pre-chamber spark plug in order to combust the air-fuel mixture during the exhaust stroke. In this way, a temperature of the pre-chamber may be increased, which may decrease a soot load of one of a pre-chamber air-injector, a pre-chamber fuel injector, and the pre-chamber spark plug.

Methods and systems are provided for an engine having a pre-chamber ignition system. In one example, a method may include adjusting a valve coupled between a pre-chamber of an engine cylinder and a main chamber of the engine cylinder between a fully open position and a fully closed position based on whether pre-chamber ignition is desired or direct spark ignition is desired. In this way, the engine may be operated with direct spark ignition during conditions when pre-chamber combustion has reduced stability without including additional spark plugs and air injectors.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber system. In one example, a method includes flowing gases from a pre-chamber to a cylinder of an engine prior to fueling the cylinder during a combustion cycle, adjusting a composition of the gases by adjusting at least one of an air injection amount to the pre-chamber and a fuel injection amount to the pre-chamber, and igniting an air-fuel mixture in the cylinder via a pre-chamber ignition event, the air-fuel mixture in the cylinder including the gas from the pre-chamber. In this way, combustion qualities in the cylinder may be adjusted in order to increase a performance and/or an efficiency of the cylinder.

A fuel injection system for an aircraft engine has: a first fuel injector having a first actuation inlet, a first fuel inlet connected to a fuel source, and a first fuel outlet connected to the at least one combustion chamber, the first fuel injector defining a first pressure ratio; a second fuel injector having a second actuation inlet, a second fuel inlet connected to the fuel source, and a second fuel outlet connected to the at least one combustion chamber, the second fuel injector defining a second pressure ratio; and an actuation fluid system having a circuit connected to the first actuation inlet and to the second actuation inlet, the first outlet pressure different than the second outlet pressure by having one or both of the first pressure ratio different than the second pressure ratio and a first actuation pressure different than a second actuation pressure.