Abstract: A method and apparatus is described for cleaning the fuel injection system of a vehicle without disassembling the fuel injectors from the vehicle engine. The apparatus includes a pump separate and apart from the vehicle for feeding fuel into the fuel supply system and a controller for controlling the pump. The controller operates at least one fuel injector while the injector is disposed in operable association with said vehicle engine, and the pump operates in a fuel feeding mode and in a fuel withdrawing mode whereby to retract fuel from the system. The system associates said pump with said fuel supplying system and disables said fuel supplying system to permit said pump to be the sole source of the fuel supply for said at least one fuel injector.