DUAL FUEL INJECTOR AND METHOD

A fuel injector for a dual fuel system includes an injector housing, and a dual concentric check assembly in the injector housing and including an inner check movable to open and close a first nozzle outlet, and an outer check movable to open and close a second nozzle outlet. A fuel flow clearance is defined between the inner check and the outer check for supplying the first fuel to a first nozzle outlet. A tight guide clearance is defined between the inner check and the outer check, and a tight guide clearance is defined between the outer check and the injector housing. A plurality of fuel supply orifices extend through the inner check to fluidly connect a fuel inlet to the fuel flow clearance. The fuel injector may function to inject two different liquid fuels, such as methanol and diesel. Related apparatus and methodology is also disclosed.