Method of reducing noise for a modular fuel injector with a harmonic annular damper member

1. A method of maintaining operational noise of a fuel injector at a predetermined noise level, the fuel injector having a body extending along a longitudinal axis and a valve group subassembly, the valve group subassembly including an inlet tube having a portion disposed within the body, the method comprising:

reducing the amplitude of vibration of the inlet tube being transmitted across an annular gap formed between an outer circumferential portion of the inlet tube and the body during operation of the fuel injector with a damper member disposed in the inlet tube, the damper member having an outer surface cincturing an inner surface about the longitudinal axis between first and second terminus to define an aperture to permit fluid communication between an inlet end of the fuel injector and a filter, the first and second terminus being spaced apart at a first distance less than a second distance between the longitudinal axis and the inner surface of the annular damper member; and

quantifying the reduction of the amplitude of vibration in the form of a standardized measured noise level output.

2. The method of claim 1 , wherein the reducing comprises increasing the mass of at least one stationary component of the valve group assembly.

3. The method of claim 2 , wherein the at least one component of the valve group assembly comprises the inlet tube.

4. The method of claim 2 , wherein the quantifying comprises:

measuring the average sound level produced by the fuel injector by a sound level meter in decibel-A-weighted (dBA) mode, while the fuel injector is operated according to the Society of Automotive Engineers Testing Standard for Low Pressure Gasoline Fuel Injector J1832 (Feb. 2001) with and without the reducing of the amplitude of vibration; and verifying a reduction in noise output of the fuel injector of at least 1.0 dBA.