Fuel injection systems for internal combustion engines

A fuel injection system for an internal combustion engine, including at least one injector nozzle, a fuel store, and at least one injector valve which is connected to receive fuel from the fuel store and which, when open, allows fuel from the store to be discharged by the said at least one injector nozzle, a metering valve operable to meter fuel continuously to the store at a rate dependent on an engine operating condition, and control means operable to open the injector valve intermittently whereby when the injector valve is closed, fuel delivered by the metering valve to the store is stored therein, the amount stored being dependent on the length of time during which the injector valve is closed and the metering rate of the metering valve, and when the injector valve opens, the stored amount of fuel is discharged by the injector nozzle, fuel being thereafter metered directly by the metering valve, through the store and injector valve, to the injector nozzle and discharged thereby until the injector valve closes.