To provide a mechanical governor for a train type fuel injection pump capable of enhancing the low-temp. starting characteristic of a Diesel engine, suppressing the product costs and enlargement in the size.

An oil damper 33 to suppress the motion of a control rack 11 in the injection amount decremental direction is installed in the housing 2 of a mechanical governor 1, and thereby the sliding resistance of a piston 28 of this oil damper 33 hinders a cam plate 14 from rotating in the injection amount decremental direction even if the viscosity of a lubricating oil in the governor housing 2 heightens remarkably when the outside air temp. is very low to lead to increase in the sliding resistance of the control rack 11, and thus the control rack 11 moves in the injection amount incremental direction by the energizing force of a cancel spring 19. That is, the acting force of an adjusting lever 16 can serve as a protruding force of the control rack 11, and the low-temp. starting characteristic is enhanced.