Fuel injection timing adjustment control system for fuel injection pump, and internal combustion engine

In order to simplify the device structure and reduce costs, an electronic governor (11) compares a control air pressure command, which is output from the electronic governor (11) to an electro-pneumatic converter (16), and a control air pressure current value, which is input to the electronic governor (11) from a pressure transmitter (32), and when the difference therebetween exceeds a threshold value, a switching signal is output from the electronic governor (11) to a flow path switching valve (33), thereby switching the flow path of the control air, and the control air, which has been output from an air tank (17) and adjusted to a specific pressure by a pressure adjustment valve (34), is guided to timing rack actuators (14) via a backup line (31) and a control air line (18) located downstream from the flow path switching valve (33), without passing through the electro-pneumatic converter (16).