Abstract: An integrated fuel system unit (10) comprises a two-stage fuel pump (16) and fuel filter (34). The fuel filter is interposed between the first and second pump stages (S1,S2) so fuel flowing between the stages is drawn through the filter. A spiral-wound fuel line (44) delivers fuel from a fuel inlet (18) to the first pump stage. Water is circulated about the fuel line to cool the fuel flowing therethrough. A fuel pressure regulator (60) in an outlet (20) of the unit diverts fuel from the engine back to a cavity (36) in which the filter is housed if an overpressure condition occurs. This fuel is then mixed with the fuel flowing between pump stages. Water also collects in the cavity and a solenoid (74) controlled water passage (72) allows this water to be entrained with fuel flowing to the second pump stage for the water and fuel to be mixed together and pumped to an internal combustion engine to be combusted therein.

Abstract: A two-stage marine fuel pump (10). A first pump stage (S1) has a fuel inlet (24) and a fuel outlet (26). A second pump stage (S2) has a separate fuel inlet (28) and fuel outlet (30). Each pump stage is stand alone such that while the outlet of the first pump stage can be routed to the inlet of the second pump stage, the pump can be otherwise configured. In these other configurations, there is one path for routing fuel to the fuel inlet of the first pump stage and from the outlet thereof, and a separate path for routing fuel to the inlet of the second pump stage and from the outlet thereof. In these alternate configurations fuel pumped from the first stage of the pump is delivered other than to the fuel inlet of the second pump stage, and fuel supplied to the inlet of the second pump stage is delivered other than from the fuel outlet of the first pump stage.