A pump unit (12) includes a pump housing (14), a pump cover (16), and an impeller (18) between the pump housing and pump cover. The pump housing and pump cover define a first channel (32) and a second channel (34) each having an inlet and an outlet. The impeller has first vanes (36) cooperating with the first channel and second vanes (38) cooperating with the second channel. The outlet of the second channel is constructed and arranged to provide fuel to an engine upon rotation of the impeller. A jet pump (38) is fluidly connected with the outlet of the first channel such that as the impeller rotates, the jet pump causes fuel to be drawn into the reservoir (37). Connecting structure (44, 44′) fluidly connects the first and second channels such that upon rotation of the impeller, fuel in the second channel flows into the first channel to prime the first channel.