Patent ID: 8011349

Claim:
A fuel injection system for an internal combustion engine, the system comprising: a plurality of pumps arranged to supply respective flows of pressurized fuel to a common accumulator volume that, in turn, supplies the pressurized fuel to a plurality of fuel injectors; an engine control unit for controlling the flow rate of pressurized fuel into the accumulator volume in response to engine load; and an engine load data input for inputting engine load data to the engine control unit; wherein the flow rate of pressurized fuel from at least one first pump of the plurality is substantially constant at a given engine speed; and wherein at least one second pump of the plurality of pumps comprises a fuel output control that is responsive to the engine control unit for varying the amount of fuel pressurized by that pump, thereby enabling the flow rate of pressurized fuel from that pump to be varied over a range of settings at the given engine speed, whereby the engine control unit controls the aggregate flow rate of pressurized fuel from the pumps into the accumulator volume.