Fuel Injectors - All

This procedure covers the removal and replacement of all six fuel injectors on the 3.5L EcoBoost V6 engine, including fuel system depressurization, fuel rail removal, and injector replacement.

Warnings

Tools required

Parts

• Fuel injector (EcoBoost 3.5L) × 6 — Use OEM Ford specification
• Fuel injector O-ring kit (upper and lower) × 1 — Use OEM Ford specification
• Fuel rail seal kit × 1 — Use OEM Ford specification
• Fuel line O-rings × 2 — Use OEM Ford specification
• Intake manifold gaskets (if disturbed) × 1 — Use OEM Ford specification

Preparation

1. Ensure engine is completely cool to touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable and wait 5 minutes for system capacitors to discharge
4. Remove engine cover by pulling upward on front clips and lifting off mounting grommets
5. Place fender covers to protect paint from fuel spills and tools
6. Photograph or label all vacuum lines, electrical connectors, and hose routing for reinstallation reference
7. Have drain pan and shop towels positioned to catch residual fuel (expect 1-2 cups)

Procedure

1. 1

   Relieve fuel system pressure
   Locate the fuel pressure relief valve on the fuel rail (passenger side, near firewall). Attach fuel pressure gauge with Schrader adapter. Slowly open valve to bleed pressure into drain pan. Verify gauge reads 0 PSI before proceeding. Alternatively, remove fuel pump fuse (fuse box location: passenger side of engine bay, fuse #27) and attempt to start engine until it stalls, then crank for 5 seconds to fully depressurize.
   ⚠️Wear safety glasses and gloves. Residual fuel under pressure will spray when valve is opened.
2. 2

   Remove air intake system
   Loosen hose clamp at throttle body and turbocharger inlet. Disconnect mass airflow sensor electrical connector. Remove air filter housing mounting bolts and lift entire intake tube and filter assembly away from engine. Disconnect any breather hoses attached to intake tube.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
3. 3

   Disconnect fuel supply line
   Locate main fuel supply line connection at rear of driver-side fuel rail. Using appropriate fuel line disconnect tool, depress locking tabs and pull line straight off rail. Be prepared for residual fuel spillage. Inspect line end for damage and cap to prevent contamination.
   ⚠Do not use screwdrivers or pliers to disconnect fuel lines as this will damage the quick-connect fittings.
   Torque spec

   Fuel Line Fittings25 Nm (18 lb-ft)
4. 4

   Remove upper intake components and brackets
   Disconnect throttle body electrical connector and coolant hoses if present. Remove PCV hose from valve cover. Unbolt and remove any wire harness brackets or clips attached to intake manifold. On this engine, you may need to remove the charge air cooler outlet pipe and associated clamps to access fuel railbolts.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)

   Mounting Bolts31 Nm (23 lb-ft)
5. 5

   Disconnect fuel injector electrical connectors
   Each injector has an individual electrical connector with a slide lock. Press down on locking tab while pulling connector straight up and away from injector. Work methodically from cylinder 1 to 6, keeping connectors organized by cylinder position. Note connector orientation for reinstallation.
   ℹ️Connector locks are fragile. Apply gentle upward pressure only after lock is fully released to avoid breaking tabs.
6. 6

   Remove fuel rail mounting bolts
   Locate the four fuel rail mounting bolts (two per rail on this twin-rail system). Remove bolts in a cross pattern to prevent rail binding. Note bolt length and position as they may vary. Once bolts are removed, fuel rails will still be retained by injector friction in manifold bores.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
7. 7

   Extract fuel rails with injectors
   Grasp fuel rail firmly with both hands. Apply steady upward force while gently rocking side-to-side to break injector O-ring seal. All three injectors should lift out with the rail as an assembly. Repeat for opposite bank. Place rails on clean shop towels. Expect residual fuel to drain from rails and injector ports.
   ⚠Do not pry against intake manifold. Excessive force in one area can crack aluminum casting or damage injector seats.
8. 8

   Remove injectors from fuel rails
   Each injector is retained by a spring clip on the fuel rail. Use pick or small flathead to pry clip upward and off rail. Once clip is removed, pull injector straight out of rail socket. Remove and discard upper O-ring from injector and lower O-ring from rail socket. Note injector orientation and any alignment tabs.
   ℹ️Injector clips are under spring tension. Control clip during removal to prevent loss.
9. 9

   Clean injector ports and inspect manifold
   Using shop towels, clean residual fuel and carbon deposits from intake manifold injector bores. Inspect each bore for cracks, damage, or debris. Check injector seats for scoring or damage. Remove any old O-ring material that may have remained in bores. Do not allow debris to fall into intake ports.
   ⚠Cover open intake ports with clean shop towels to prevent foreign material from entering cylinders.
10. 10

    Prepare and install new injectors
    Lightly lubricate new upper and lower O-rings with clean engine oil or fuel. Install lower O-ring into groove on injector body. Insert injector into fuel rail socket, aligning any orientation tabs. Install upper O-ring into fuel rail around injector. Ensure O-rings are properly seated in grooves without twists or pinching. Install retaining clip by pressing firmly until it clicks into locked position. Repeat for all six injectors.
    ℹ️Never reuse old O-rings. Always use new O-rings from injector kit even if old ones appear undamaged.
11. 11

    Install fuel rail assemblies
    Ensure injector bores in manifold are clean and dry. Align all three injectors on rail with their respective bores. Apply even downward pressure on rail to seat all injectors simultaneously. Injectors should slide in with moderate resistance. Once fully seated, rail mounting holes will align with manifold threaded holes. Do not force or cock rail at an angle. Repeat for opposite bank.
    ⚠Cross-threading or cocking fuel rail during installation will damage injector O-rings and cause fuel leaks.
12. 12

    Install fuel rail bolts
    Thread all four fuel rail mounting bolts by hand to ensure proper thread engagement. Tighten bolts in a cross pattern to specification using torque wrench. Do not overtighten as this can distort rail and cause sealing issues.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
13. 13

    Reconnect electrical and fuel connections
    Reconnect each fuel injector electrical connector, ensuring locking tab clicks into place. Verify each connection is secure with gentle pull test. Reinstall any wire harness brackets or clips removed earlier. Install new O-rings on fuel supply line end, then reconnect to fuel rail until quick-connect clicks and locks. Verify connection by pulling on line.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)

    Mounting Bolts31 Nm (23 lb-ft)
14. 14

    Reinstall intake system components
    Reinstall charge air cooler outlet pipe if removed, using new clamps if originals were damaged. Reconnect PCV hose, throttle body electrical connector, and any coolant hoses. Reinstall air intake tube and filter assembly, ensuring mass airflow sensor is connected and all hose clamps are secure. Reinstall engine cover.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
15. 15

    Prime fuel system and test
    Reconnect negative battery cable. Turn ignition to ON position (do not start) for 5 seconds, then OFF. Repeat 3-4 times to prime fuel system. Inspect all fuel connections for leaks. Start engine and allow to idle. Check for fuel odor or visible leaks at rail connections and injector seals. Monitor for rough idle or misfires indicating improper injector installation.
    ⚠️If any fuel leaks are detected, immediately shut off engine and relieve fuel pressure before investigating. Do not attempt to tighten connections with engine running.

Reassembly

1. Ensure all electrical connectors are fully seated and locked before starting engine
2. Double-check that all hose clamps and fuel line connections are tight and properly positioned
3. Verify no tools or shop towels were left in engine bay before closing hood
4. If any misfires or rough running occur after installation, recheck injector electrical connections and seating depth

Verification

• Start engine and let idle for 5 minutes, monitoring for fuel leaks at rails and connections
• Check for diagnostic trouble codes related to fuel injector circuit or mixture issues
• Perform test drive and verify smooth acceleration with no hesitation or misfires under load
• After test drive, perform final leak inspection of all fuel connections with engine off
• Verify no fuel odor is present in engine bay or cabin after repair

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