Fuel injection pump with cold start device

A fuel injection pump comprising:

• a barrel formed with a main port and a sub port;
• a plunger;
• and
• a cold start device including an injection-advancing actuator which operates a piston for opening or closing the sub port so as to change an injection timing in correspondence to temperature, wherein the plunger is moved to connect or separate the sub port and the main port to and from a fuel compression chamber,
• characterized in that the barrel is further formed with at least one exclusive overflowing sub port constantly opened regardless of the operational state of the piston, wherein the exclusive overflowing sub port is disposed between the main port and the sub port opened and closed by the piston in the slide direction of the plunger so that the positional difference of the sub port being able to be opened and closed and the exclusive overflowing sub port in the slide direction of the plunger defines the change degree of injection timing, and wherein means to adjust the position and diameter of the exclusive overflowing sub port are provided to adjust the change degree of injection timing and quantity.