A fuel system for an engine, comprising: a first flow line; an electrically driven startup pump in fluid communication with the first flow line to provide a startup flow; a main flow line; a main pump in fluid communication with the main flow line to provide a main flow; a switching valve connected to the first flow line and the main flow line and downstream of both the electrically driven startup pump and the main pump, the switching valve configured to actuate between a first position and a second position to allow fluid communication with the first flow line or the main flow line, respectively, based on a pressure differential to output either the startup flow or the main flow, wherein in the first position the switching valve is configured to select the first flow line to output the startup flow, and in the second position, the switching valve is configured to select the main flow line to output the main flow; characterized in that the switching valve selects the main flow line as a function of pressure differential between the main flow and the startup flow; and a pressure regulating valve in fluid communication with the electrically driven startup pump and configured for switching between a first position of the pressure regulating valve and a second position of the pressure regulating valve, wherein in the first position of the pressure regulating valve, the pressure regulating valve allows flow to the electrically driven startup pump and wherein in the second position of the pressure regulating valve, the pressure regulating valve allows flow to bypass the switching valve and allows excess flow back to the inlet of the electrically driven startup pump. a first flow line; an electrically driven startup pump in fluid communication with the first flow line to provide a startup flow; a main flow line; a main pump in fluid communication with the main flow line to provide a main flow; a switching valve connected to the first flow line and the main flow line and downstream of both the electrically driven startup pump and the main pump, the switching valve configured to actuate between a first position and a second position to allow fluid communication with the first flow line or the main flow line, respectively, based on a pressure differential to output either the startup flow or the main flow, wherein in the first position the switching valve is configured to select the first flow line to output the startup flow, and in the second position, the switching valve is configured to select the main flow line to output the main flow; characterized in that the switching valve selects the main flow line as a function of pressure differential between the main flow and the startup flow; and a pressure regulating valve in fluid communication with the electrically driven startup pump and configured for switching between a first position of the pressure regulating valve and a second position of the pressure regulating valve, wherein in the first position of the pressure regulating valve, the pressure regulating valve allows flow to the electrically driven startup pump and wherein in the second position of the pressure regulating valve, the pressure regulating valve allows flow to bypass the switching valve and allows excess flow back to the inlet of the electrically driven startup pump.