Patent ID: 7980223

Claim:
A fuel injection system for an engine, the engine including at least one engine cylinder and operating at a variable engine speed, the fueling system comprising: a fuel pump for supplying fuel at high pressure, the fuel pump including at least one pumping element and operating at a speed that is proportional to the variable engine speed, the at least one pumping element including a compression phase having an instant of start Pi and an instant of end Ps; an accumulation volume in communication with the fuel pump and receiving fuel at high pressure therefrom; a by-pass valve in communication with the fuel pump and the accumulation volume, the by-pass valve operating to intermittently deliver fuel at high pressure from the fuel pump to the accumulation volume, the by-pass valve operating to deliver fuel to the accumulation volume during only a portion of the compression phase such that a fuel delivery instant of start T 0 occurs after the compression phase instant of start Pi and a fuel delivery instant of end T 1 occurs before the compression phase instant of end Ps; and at least one fuel injector in communication with the accumulation volume and receiving fuel at high pressure therefrom, the at least one fuel injector actuatable independently of the by-pass valve to inject fuel into the engine cylinder during an injection phase that occurs within the compression phase.