Ford Focus Service Manual: Fuel System - General Information

The fuel system consists of:

• a Mechanical Returnless Fuel System (MRFS) .
• a fuel rail.
• a Multi-Port Fuel Injection (MFI) system.
• a standard fuel tank.
• fuel, vapor and brake tubes in an integrated bundle assembly attached to the underside of the vehicle by retaining clips.
• a lifetime fuel filter serviced as part of the Fuel Pump (FP) module.
• a one-fourth turn fuel tank filler cap.
• an Inertia Fuel Shutoff (IFS) switch.
• a FP module containing:
  • an electric FP , which provides pressurized fuel to the fuel rail.
  • a fuel filter.
  • a fuel level sender.
  • a check valve, which maintains system pressure after the FP is shut off.
  • a pressure relief valve for overpressure protection in the event of restricted fuel flow.
• a fuel tank filler pipe containing:
  • a recirculation tube.
  • a fresh air hose.
  • a restrictor plate to permit only unleaded fuel to be pumped into the tank.

The fuel tank filler pipe cannot be modified in any way.

The vehicle is equipped with electronic MFI fuel injection that is supplied by a MRFS .