The main function of fuel injectors is to spray oil, in addition to spraying the required amount of oil in each cylinder according to the amount of oil pumped from the pump. The average fuel pressure of a 3rd generation piezoelectric fuel injector is about 26,000 psi.
Idle air control actuator / Idle speed control actuator, but its function is to calculate the engine temperature and electrical load so that the engine rpm does not go down, and the ECU commands it to act when it needs to do so