Abstract: Disclosed is a method of operating an internal combustion engine (20) with a fuel injection system (11;12) including an injector (12) for delivery of a fuel-gas mixture to a combustion chamber (60) of the engine (20). The engine (20) includes a gas supply system (11;13) pressurized at start-up through a pump-up sequence to a desired pressure for injection of fuel to the engine (20). In the pump-up sequence, the injector (12) is opened allowing pressurized gas to flow from the combustion chamber (60) through the injector (12) and into the gas supply system (11;13). This pressurizes the gas supply system (11;13) when pressure in the combustion chamber (60) is higher than the pressure in the gas supply system (11;13).

Abstract: A method of operating an internal combustion engine to control "knock" therein, by injecting a metered quantity of fuel entrained in a gas directly onto the engine combustion chamber and controlling the timing of injection of the fuel into the combustion chamber. The control of timing of injection being effected by setting the time of the end of the period of injection in relation to the engine cycle, and reducing the duration of the injection period in response to detection of "knock" in the engine above a predetermined level. The duration of injection is reduced in a stepwise manner one step each cycle until "knock" is eliminated or reduced below the predetermined level.

Abstract: A fuel injection system for a multi-cylinder internal combustion engine, which includes a rigid elongated unitary member incorporating a gas supply duct, a fuel supply duct and a fuel return duct, each of which extends in the direction of elongation of the unitary member. A separate fuel metering device and fuel injecting device is provided for each engine cylinder. The fuel metering device is arranged to deliver metered quantities of fuel to the fuel injection device and is in communication with the fuel supply and fuel return ducts so that fuel can be circulated through each of the fuel metering devices. The fuel injecting devices are each in communication with the gas duct and communicable with one of the engine cylinders. The fuel injection devices are adapted to effect delivery of a metered quantity of fuel entrained in gas supplied from the gas duct when the fuel injecting device is in fluid communication with a cylinder.