Fuel Pump: Description and Operation

FUEL PUMP
The electric fuel pump located in the fuel tank consists of armature, magnet, impeller, brush, check valve, etc.. The ECM controls its ON/OFF operation as described under "Fuel Pump Control System." Description and Operation

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 inlet port, and with its pressure increases, it is discharged through the outlet port.
The fuel pump also has a check valve to keep some pressure in the fuel feed line even when the fuel pump is stopped.





ECM controls ON/OFF operation of the fuel pump by turning it ON via the fuel pump relay under any of the following conditions.
- For 2 seconds after ignition switch ON.
- While cranking engine (while engine start signal is inputted to ECM).
- While camshaft position sensor (CMP sensor) signal is inputted to ECM.