Abstract: A fuel injection pump for an internal combustion engine is provided with a graduated sector on a part which rotates with the cam shaft of the pump and which is disposed within the pump casing. The casing is provided with a viewing aperture through which the graduated sector can be seen. Indicating means are provided in the viewing aperture so as to co-operate with the graduated sector to indicate the angular position of the pump shaft, thereby facilitating setting of the timing of the pump shaft rotation relative to the rotation of the engine crank shaft.