Abstract: A device for preventing fuel pump air ingestion in a diesel fuel system includes a diesel engine having a plurality of injectors. The injectors receive a supply of diesel fuel from a fuel injection pump at a high pressure. The fuel injection pump receives the supply of diesel fuel from a transfer pump at a transfer pressure through a transfer pressure gallery. The supply of diesel fuel is stored in a fuel tank coupled to the transfer pump through a fuel line. To prevent air from entering the diesel fuel system, a low pressure sensing switch is coupled to the transfer pressure gallery and senses the transfer pressure. When the transfer pressure drops below a predetermined pressure a controller disables the fuel injection pump. Once the transfer pressure rises above the predetermined pressure level the controller enables the fuel injection pump.