Abstract: An injection unit which is associated with a cylinder of a multicylinder diesel engine and comprises an injection nozzle and an injection piston pump which is disposed in a common housing and is driveable by a cam shaft. Said pump comprises a rotatable pump piston which is displaceable in a pump cylinder and has two control edges disposed axially spaced from each other for at least one fuel passage of the pump cylinder. To obtain the desired injection accuracy by accurately observing only a few dimensions during the production and without further tests, measuring and adjusting operations, the pump piston (3) and the pump cylinder (14) each comprise at least one stop face (24, 25) extending transversely preferably normal to the pump longitudinal axis. Said faces cooperate in the basic position of the pump piston (3) assumed in the installation of the unit in the engine directly or indirectly with simultaneous rotational position fixing of the pump piston (3).