Common rail injector with separately controlled pilot and main injection

The present invention relates to common rail fuel injectors, and includes an example of such an injector (22), a fuel injection system (10) employing such an injector (22), and a method of injecting fuel. The fuel injector (22) includes an injector body (40), a fuel pressurization chamber (75), a nozzle chamber (81), a needle control chamber (85), a needle control spill outlet (87), a fuel inlet (41), and a nozzle outlet (89). The present fuel injection system (10) includes a source of intermediate pressure fuel (16), a low pressure fuel reservoir (12), a needle valve (80), a flow control valve (60), and at least one of the present fuel injectors (22). The method of injecting fuel consists of the steps of injecting fuel at an intermediate pressure at least in part by fluidly connecting the injector's nozzle chamber (81) to the intermediate fuel source (16), and injecting fuel at a high pressure at least in part by exposing a pressure intensifying element (70) to the source of intermediate pressure fuel (16).