Fuel injector having spring seat allowing spring rotation and alignment

The present invention provides a fuel injector having a fuel inlet, a fuel outlet, and a fuel passageway extending along an axis between the fuel inlet and the fuel outlet. The fuel injector includes a body having an inlet portion, an outlet portion, and a neck portion disposed between the inlet portion and the outlet portion. An armature is disposed within the neck portion of the body and displaceable along the axis relative to the body. A spring is disposed within the neck portion and applies a biasing force to the armature. The spring has a downstream end disposed proximate the armature and an upstream end opposite from the downstream end. An adjusting tube is disposed within the neck portion of the body and proximate to the upstream end of the spring. The adjusting tube varies the biasing force applied by the spring to the armature. A spring seat engages one of the spring ends and permits spring movement that counteracts parasitic forces arising due to compression and extension of the spring, and applies the biasing force substantially along the axis.