An apparatus (1) is used for cleaning the fuel injection system of a motor vehicle. The apparatus (1) includes an adaptor body (3) which fits onto a container (2). The adaptor body (3) has an inlet port (6) and an outlet port (7) which connect the interior of the container (2) to the fuel system of the motor vehicle. The outlet port (7) has an extension pipe (16) which has an opening adjacent the bottom of the container (2) while the inlet port (6) opens adjacent the top of the container (2). The apparatus (1) is used to direct cleaning solvent (26) to the fuel system of the motor vehicle.
