Abstract: A fuel injection system (10) for delivering metered amounts fuel into the combustion chamber or cylinder of an engine. The fuel delivered can selectively comprise a gaseous fuel, a liquid fuel or a fuel mixture comprising the gaseous fuel and the liquid fuel. When the fuel delivered comprises a mixture of the gaseous fuel and the liquid fuel, the quantity of liquid fuel comprises a metered quantity. The quantity of gaseous fuel also comprises a metered quantity, with the metering of the gaseous fuel being regulated by prediction. The injection event involves delivering the liquid fuel and the gaseous fuel, with the metering of the gaseous fuel delivered being adjusted to allow for the quantity of liquid fuel delivered with the gaseous fuel. The injection system (10) comprises a liquid fuel circuit (11) and a gaseous fuel circuit (13), both communicating with a fuel delivery injector (15) that delivers fuel to the combustion chamber.

Abstract: A fuel injection system (10) for delivering metered amounts fuel into the combustion chamber or cylinder of an engine. The fuel delivered can selectively comprise a gaseous fuel, a liquid fuel or a fuel mixture comprising the gaseous fuel and the liquid fuel. When the fuel delivered comprises a mixture of the gaseous fuel and the liquid fuel, the quantity of liquid fuel comprises a metered quantity. The quantity of gaseous fuel also comprises a metered quantity, with the metering of the gaseous fuel being regulated by prediction. The injection event involves delivering the liquid fuel and the gaseous fuel, with the metering of the gaseous fuel delivered being adjusted to allow for the quantity of liquid fuel delivered with the gaseous fuel. The injection system (10) comprises a liquid fuel circuit (11) and a gaseous fuel circuit (13), both communicating with a fuel delivery injector (15) that delivers fuel to the combustion chamber.

Abstract: A method of vaporising fuel in a spark-ignition engine using the supply of heat into the cylinder to wholly or partly vaporise the fuel, the heat being supplied by operation of a spark plug. One or more engine conditions can be sensed, such as engine temperature, coolant temperature, the cumulative amount of fuel supplied, engine speed or the time elapsed since start-up, and the spark plug operated to supply heat in response to such condition(s). The heat can be supplied by operating the spark plug more than once in an engine cycle or by operating the spark plug to form a spark over a time period determined in response to the engine condition. An AC circuit can be used to produce a substantially continuous spark over a defined time period or suitable angular duration. The heat can be supplied by operating the spark plug prior to engine cranking, to generate heat in the cylinder at engine start-up. A method of reducing spark plug fouling is also disclosed.

Abstract: A gaseous fuel injection system (10) for delivering metered amounts of gaseous fuel into the combustion chamber of an engine, and also a method for injecting gaseous fuel directly into a combustion chamber of an internal combustion engine. The gaseous fuel injection system (10) comprises a body structure (11) defining a holding chamber (13) from which a fluid mixture contained therein can be subsequently delivered by a delivery injector (15) into the combustion chamber. The delivery injector (15) has an inlet (16) communicating with the holding chamber (13) and an outlet (18) for communication with the combustion chamber. The holding chamber (13) is adapted to receive a quantity of gaseous fuel from a fuel source through an inlet port (17). The holding chamber (13) is also adapted to receive a metered quantity of a supplementary gaseous fluid through a metering means (21). In one arrangement, the supplementary gaseous fluid may function as a diluent for the gaseous fuel.