A multiple plunger injection pump for an internal combustion engine, in which plungers are arranged in alignment in one line. A housing which holds the governor within chambers, is arranged so that all chambers are filled with fuel. The fuel is supplied to the chambers under pressure for purposes of lubricating and cooling the moving parts. The housing has bores into which are fitted pump barrels. The plungers are movable in the barrels. A control rod used for regulating the pump metering, is linked to the base of the barrels for rotational movement of the plungers. A spring presses tappets against a cam for reciprocal movement of the plungers which are provided with spring discs in proximity of a passage supplying fuel to the fuel supply means. The fuel supply means is spaced from the chamber of driving means by the discs, and is connected to the driving chamber by the driving means, through gaps of the spring discs. Part of the fuel supply flows to the chamber of the driving means through the gaps.