An in-tank fuel supply unit is provided for supplying fuel from a fuel tank to an engine. The fuel supply unit generally comprises a fuel delivery module and a jet pump assembly selectively attachable to the fuel delivery module. The fuel delivery module has a housing defining a reservoir and includes a fuel pump for pressurizing fuel in the reservoir. The jet pump assembly has a suction tube defining a suction chamber and a nozzle situated inside the suction chamber. The nozzle receives pressurized fuel from the fuel pump and sprays the fuel from a nozzle tip at high velocity to draw additional fuel into the suction chamber through an inlet formed in the suction tube.