Injection controller and injection control method

An injection control method performed by a processor that controls a fuel injection quantity in each cylinder of an engine including a plurality of cylinders, the injection control method comprising:

• an acquiring step of acquiring an intake air pressure of each of the cylinders from an intake air pressure sensor provided in an intake path;
• an injection quantity determining step of determining, for each of the cylinders, on the basis of the intake air pressure in one intake stroke, a fuel injection quantity in a next intake stroke in the cylinder;
• an instruction determining step of determining that an instruction operation for making an instruction to increase or reduce a rotation speed of the engine has been performed on the basis of the intake air pressure in one of the cylinders;
• and
• a transient response step of performing transient response control to apply the fuel injection quantity for the next intake stroke in the one cylinder determined in the injection quantity determining step also to the fuel injection quantity in the next intake stroke in the cylinders other than the one cylinder when it is determined that the instruction operation has been performed in the instruction determining step.