Volumetric efficiency and injector performance?

I ask for help in the correct entry of values!
My small gasoline engine.
Engine brand D4F
Injector power system
Type of engine in-line
Engine displacement 1149 cm ³
Number of cylinders 4
Valves per cylinder 4
Stroke 76.8 mm
Cylinder diameter 69 mm
Compression ratio 9.8
Power 75 - 76
Torque 105 - 107 Nm
Environmental Standards Euro 4/5
How can I calculate the injector performance, for how many cylinders should it be calculated?
And how to calculate volumetric efficiency?