How does fuel injection work?

FI works through an array of diffrent sensors that tell the cars computer how much fuel to put into each cylinder and when, the computer on many newer vehicles go through learning cycles, by driving around the car learns how you drive and wether to adjust for economy or for power. So if you want it to perform better you may want to drive diffrently or increase air flow by getting a bigger throttel body and cold air intake, and maybe a programmer chip to make your ecu behave diffrently