METHOD AND APPARATUS TO REDUCE ENGINE NOISE IN A DIRECTION INJECTION ENGINE

摘要

A method to reduce engine noise in a multi-cylinder direct injection internal combustion engine. The internal combustion engine includes a high pressure fuel pump having both an inlet valve fluidly connected to a fuel source and an outlet valve typically connected to a pressurized fuel rail. In order to reduce engine noise, especially at low engine speeds, the timing of the opening of either the fuel pump inlet valve or fuel pump outlet valve is varied so that it coincides with the opening of the fuel injectors.