Fuel Supply Line: Service and Repair

Multiport Fuel Injection (MFI) systems are equipped with an electric fuel pump module that provides fuel to the engine at higher pressure than conventional fuel systems. A fuel return system is also provided. All fuel hose/tube connections are made with push connect fittings, and all flexible hoses are serviced as assemblies. The metal tubes attached to the vehicle underbody may be serviced. The metal underbody tubes must be cut and formed out of rolls of fuel system service tubing available at the dealerships.

A damaged section of tubing can be cut out of the existing line and replaced by a comparable service tubing section, spliced into the line by means of threaded fasteners and connectors.

CAUTION:All flexible hoses must be serviced as assemblies.

Fuel Tubes, Steel

CAUTION:The use of copper tubing is NOT recommended due to fuel contamination.

CAUTION Flexible bulk fuel hose must NOT be used to service tubing in high pressure fuel systems.

Removal
1. Drain the fuel from the fuel tank: Service and Repair

2. Disconnect the tube(s) at the fuel tank and engine. Remove the tubes from the holding clips along the underbody. Remove all damaged hoses and tube sections.

Installation
1. Cut a new section of tubing to approximately the same length as the section to be replaced, allowing for the threaded connectors/fasteners.

2. Bend the tube section to conform to the contour of the original tube.

3. Square the ends of the cut tubing with a file. Remove burrs. Blow out any particles with compressed air.

4. Position the tubes in the underbody clips. Do not tighten at this time.

5. Assemble the fitting by sliding the nut over the tubing with threaded (open) end out.

6. Slide the ferrule on the tubing with the culling edge out; the large head end should be inside of the nut.

7. Lubricate the ferrule and the threads on the fasteners with engine oil meeting Ford specification ESE-M2C153-E.

8. Bottom the tube in the fitting, and tighten the nut until the ferrule just grips the tube. When the tube can no longer be turned by hand, the ferrule has started to grip the tube.

9. After the ferrule grips the tube, tighten the nut one full turn.

10. Tighten the fuel tube to the underbody clips to secure the fuel tubes.

Fuel Line Service Parts:

Splicing Nylon to Nylon

Procedure
1. Relieve fuel system pressure: Fuel Pressure Release

2. Cut out damaged section of tubing and retain as a guide.

3. Cut a section of service tubing type 11 or 12 nylon 7.9 mm (5/16 inch) diameter to same length as damaged section of tubing.

4. Select proper 7.9 mm (5/16 inch) barbed connectors for completing splice. Two connectors are required for each splice.

NOTE: To make hand insertion of barbed connectors into nylon easier, tube end must be soaked in a cup of boiling water for one minute immediately before pushing barbs into nylon.

5. Install barbed connectors into each end of replacement tubing using boiling water.

6. Install clips onto any tubes which might be difficult to access once final splices are completed.

7. Install four keystone clamps loosely onto original nylon tubing before beginning next step.

8. Complete splice of replacement nylon to original nylon tubing at both ends.

9. Tighten clamps in locations shown in illustration.

10. Install any remaining clips which were removed for this service and check that tubes are secure in original clips.

11. Fill fuel tank, start engine and check for leaks.