Double concentric inlet tube for setting armature/needle lift and method of manufacturing same

A method of setting armature/needle lift in a fuel injector having an external inlet tube fixedly connected to a body, an internal inlet tube having an upstream end and a downstream end extending along a longitudinal axis, an armature/needle assembly including an armature having an upstream end and a needle having an upstream end connected to the armature, and a seat disposed in the body, the method comprising:

• inserting a lift pin into the upstream end of the internal inlet tube;
• inserting a lift check gauge through the lift pin into the internal inlet tube such that a downstream end of the lift check gage engages the upstream end of the needle and such that the armature/needle assembly is biased downstream, the needle engaging the valve seat;
• fixedly positioning an upstream end of the lift check gage;
• moving the internal inlet tube downstream such that the downstream end of the internal inlet tube engages the armature, the internal inlet tube having first and second ends contacting an inner surface of the external inlet tube along the longitudinal axis, and a middle portion disposed between the first and second ends, the middle portion being spaced from the external inlet tube so that the middle portion avoids contact with the external inlet tube, the external inlet tube contiguous to a non-magnetic shell along the longitudinal axis, and the non-magnetic shell has a portion contiguous to the body along the longitudinal axis;
• moving the lift pin and the internal inlet tube upstream a predetermined distance as measured by the lift check gage;
• removing the lift check gage and the lift pin from the internal inlet tube;
• and
• securing the internal inlet tube to the external inlet tube.