Fuel injector spring force calibration tube with internally mounted fuel inlet filter

A fuel injector having inlet and discharge ends and comprising:

• a fuel tube at the inlet end through which fuel is admitted to a fuel passage extending to the discharge end;
• a valve at the discharge end and having a valve element reciprocable against and away from a valve seat to prevent or allow fuel discharge through the valve seat;
• a biasing spring having a first end operatively engaging the valve element;
• a calibration member having first and second ends and defining a portion of the fuel passage through which fuel must pass to the injector discharge end, the calibration member having adjacent the first end an enlarged portion engaging the fuel tube with an interference fit, the second end defining a spring seat operatively engaging the spring and biasing the spring against the valve element with a set force for controlling fuel discharge from the injector, the calibration member being adjustable within the injector for calibrating the spring to establish the set force;
• and
• a fuel filter mounted within the calibration member and effective to filter all the fuel passing through the calibration member defin portion of the fuel passage, said filter having an enlarged hollow base received within the enlarged portion of the calibration member and mounting the filter in the calibration member.