Modular fuel injector having an integral filter and an adjustment assembly

A fuel injector (100) for use with an internal combustion engine. The fuel injector comprises a valve group subassembly (200) and a coil group subassembly (300). The valve group subassembly (200) includes a tube assembly having a longitudinal axis that extends between a first end and a second end; a seat that is secured at the second end of the tube assembly and that defines an opening; an armature assembly (260) that is disposed within the tube assembly; a spring (270) that biases the armature assembly toward the seat; an adjusting tube (280) that is disposed in the tube assembly and that engages the spring for adjusting a biasing force of the spring (270); a filter (284) that is at least within the tube assembly. The coil group subassembly (300) includes a solenoid coil (310) that is operable to displace the armature assembly with respect to the seat.