Fuel System: General Description: Operation
When power is supplied to the fuel pump, the motor in the pump runs and so does the impeller.
This causes a pressure difference to occur between both sides of the impeller as there are many grooves around it.
Then the fuel is drawn through the port, and with its pressure increased it is discharged through the outlet port.
The fuel pump also has a relief valve to prevent excessive rise of the discharge pressure and a check valve to keep some pressure in the fuel feed line even when the fuel pump is stopped.
When the solenoid coil of the injector is energized by ECM (PCM), it becomes an electromagnet and attracts the armature. At the same time, the ball valve which is incorporated with the armature pipe opens and the injector which is under the pressure injects fuel. As the lift stroke of the ball valve of the injector is set constant, the amount of fuel injected at one times is determined by the length of time during which the solenoid coil is energized (injection time).