An internal combustion engine includes an injector that injects fuel into a cylinder. A plunger-type fuel pump pumps the fuel to the injector from a fuel tank. A control system for the fuel pump includes a unit for determining an injection start timing of the injector, and a drive unit for driving the fuel pump for a second predetermined time that starts a first predetermined time earlier than the injection start timing. This control system makes stable combustion possible even when there are pressure variations in the fuel pumped to the injector.