Method and system for direct injection noise mitigation

摘要

A method is provided which mitigates the noise of a direct injection system in a port fuel injection and direct fuel injection (PFI-DI) engine and reduces NVH hardware. During a cold-start, the engine idle speed may be increased to mitigate the direct injection noise and during a warm idle, the engine cooling fan may be turned on during a direct injector cleanout cycle to mitigate the direct injection noise. This allows the PFI-DI engine to be run more efficiently without concern of the noise produced by the direct injectors and high pressure pump of the direct injection system.

主权项

1. A method, comprising:
during a first engine cold start, operating at a first higher idle speed while performing direct fuel injection; during a second engine cold start, operating at a second, lower idle speed while performing only port fuel injection; and during warmed up idle speed operation with an engine temperature below a temperature at which a cooling fan is activated, activating the cooling fan while performing a direct injector cleanout cycle.