FUEL PUMP UNIT CONSTRUCTION/OPERATION [AJ (3.0L Duratec)]
BUE011413350N04
Fuel Pump Unit
• Consists of a fuel filter (high-pressure), pressure regulator, fuel pump, fuel reserve cup, and fuel filter (low-pressure).
• A pressure regulator is built-in due to the adoption of a returnless fuel system.
• The fuel pump unit cannot be disassembled.
• Fuel in the fuel reserve cup is suctioned out through the fuel filter (low-pressure) by the fuel pump, and pumped to the fuel filter (high-pressure) on the outside of the fuel tank. Additionally, returned fuel that has been pressure adjusted by the pressure regulator returns to the fuel reserve cup or the fuel tank.
• If the return pressure exceeds a given value, the relief valve activates to discharge fuel into the fuel pump unit. As a result, return pressure is maintained at the specified value or less.
Pressure Regulator
• Built into the fuel pump unit due to adoption of a returnless fuel system.
• Cannot be removed because the pressure regulator and fuel pump unit are an integrated construction.
• Consists of a spring, relief valve, and diaphragm.
• Pressure regulates fuel discharged by the fuel pump to approx. 440 kPa {4.49kgf/cm2, 63.8 psi} using the spring, diaphragm, and relief valve, and then pumps it to the fuel distributor.
• If the fuel pressure exceeds approx. 440 kPa {4.49kgf/cm2, 63.8 psi}, the relief valve opens and unnecessary fuel pressure (fuel) is purged.
