This procedure covers the removal and installation of the fuel rail assembly on a 2021-2024 Ford F-150 with the 3.5L EcoBoost V6 engine, including fuel system depressurization and fuel injector handling.

Warnings

Tools required

Parts

• Fuel rail assembly (if replacing) × 1 — Use OEM specification
• Fuel injector O-rings (upper and lower) × 6 — Use OEM specification
• Fuel line O-rings × 2 — Use OEM specification
• Engine cover grommets (if damaged) × 4 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery cable and wait 2 minutes for system capacitors to discharge
4. Remove engine cover by pulling upward on all four corners to release grommets
5. Place absorbent pads or towels around fuel rail area to catch residual fuel
6. Verify fire extinguisher is accessible and functional

Procedure

1. 1

   Depressurize fuel system
   Locate the fuel pressure test port on the fuel rail (driver side, near firewall). Attach fuel pressure gauge to the Schrader valve. Slowly open the valve to release fuel pressure into an approved container. Monitor gauge until pressure reads zero. Close valve and remove gauge. Wipe area clean of any spilled fuel.
   ⚠️Release pressure slowly to prevent fuel spray. Keep face and body away from test port during depressurization.
2. 2

   Disconnect fuel supply line
   Locate the fuel supply line connection at the front of the fuel rail (passenger side). Using the appropriate fuel line disconnect tool, depress the locking tabs while pulling the line straight back from the rail. Have shop towels ready to catch residual fuel. Inspect the line end for damage and note the condition of the O-ring for replacement.
   ⚠Do not bend or twist fuel line during disconnection. Use only the proper disconnect tool to avoid damaging the quick-connect fitting.
3. 3

   Disconnect electrical connectors
   Disconnect the electrical connector from each of the six fuel injectors by pressing the red safety tab and pulling the connector straight up. Disconnect the fuel rail pressure sensor connector located on the driver side of the fuel rail. Use a small flathead screwdriver to release the connector lock if needed. Secure connectors away from work area.
4. 4

   Remove charge air cooler outlet pipe
   Loosen the hose clamps at both ends of the charge air cooler outlet pipe (connects turbocharger outlet to throttle body). Remove the pipe to gain access to the fuel rail mounting bolts. Set pipe aside in a clean area to prevent debris contamination.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
5. 5

   Disconnect vacuum line
   Locate the fuel pressure regulator vacuum line on the driver side of the fuel rail. Carefully disconnect the vacuum line by releasing the retaining clip and pulling straight off. Inspect line for cracks or damage.
6. 6

   Remove fuel rail mounting bolts
   Locate the four fuel rail mounting bolts (two on each side of the rail). Using an 8mm socket, remove all four bolts in a crisscross pattern to evenly release rail tension. Keep bolts organized for reinstallation.
   Torque spec

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

   Remove fuel rail assembly
   Carefully lift the fuel rail assembly straight up with even pressure on both ends. The fuel injectors will pull out of the intake manifold ports simultaneously. If rail is stuck, gently rock side-to-side while pulling upward. Do not pry or use excessive force. Once free, keep rail level to prevent fuel spillage and set on clean shop towels.
   ⚠Fuel injectors are delicate precision components. Do not allow them to swing or impact hard surfaces while attached to the rail.
8. 8

   Remove and inspect fuel injectors
   If replacing fuel rail or servicing injectors, remove the retaining clips securing each injector to the rail. Carefully pull each injector from the rail. Remove and discard all upper and lower O-rings from each injector. Inspect injector tips for carbon buildup or damage. Inspect fuel rail for cracks, especially around mounting boss areas.
9. 9

   Clean intake manifold ports
   With fuel rail removed, inspect the six fuel injector ports in the intake manifold. Remove any debris or old O-ring material using a clean lint-free cloth. Do not allow any debris to fall into the intake ports. Cover ports with clean shop towels if extended service time is needed.
   ⚠Do not use solvents or cleaners that could drip into intake manifold. Foreign material in intake can cause engine damage.
10. 10

    Install new O-rings on fuel injectors
    Lubricate new upper and lower O-rings with clean engine oil. Install lower O-rings into the grooves on each injector body. Install upper O-rings into the fuel rail injector bores if injectors were removed. Ensure O-rings are properly seated without twisting or pinching.
11. 11

    Install fuel injectors to rail
    If injectors were removed, insert each injector into the fuel rail bore, aligning the electrical connector orientation. Install the retaining clip onto each injector, ensuring it clicks into place and locks the injector securely. Verify each injector can rotate slightly but cannot be pulled out.
12. 12

    Install fuel rail assembly
    Carefully position the fuel rail assembly over the intake manifold, aligning all six injectors with their respective ports. Apply even downward pressure on both ends of the rail simultaneously, ensuring all injectors seat fully into the manifold. The rail mounting bosses should sit flush against the manifold.
    ⚠Ensure injectors enter ports straight without binding. Cocked injectors can damage O-rings and cause fuel leaks.
13. 13

    Install fuel rail mounting bolts
    Install all four fuel rail mounting bolts finger-tight in a crisscross pattern. Using a torque wrench and 8mm socket, torque all bolts to specification in two stages: first to 6 Nm, then to final specification in crisscross pattern to ensure even seating.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
14. 14

    Reconnect vacuum and fuel lines
    Reconnect the fuel pressure regulator vacuum line, ensuring the retaining clip locks in place. Install new O-ring on fuel supply line if old one shows wear. Push fuel supply line into rail quick-connect fitting until it clicks. Pull back on line to verify it is locked.
    ⚠Verify fuel line connection is fully locked. An incomplete connection will cause fuel leaks under pressure.
15. 15

    Reconnect electrical connections
    Reconnect each fuel injector electrical connector, ensuring they click into place. Reconnect the fuel rail pressure sensor connector. Verify all connectors are fully seated and locked.
16. 16

    Reinstall charge air cooler outlet pipe
    Position the charge air cooler outlet pipe between turbocharger outlet and throttle body. Tighten hose clamps at both ends to specification using a torque wrench. Ensure pipe is properly seated in both connections.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)

Reassembly

1. Reinstall engine cover by aligning grommets with mounting posts and pressing down firmly until seated
2. Reconnect negative battery cable
3. Do not start engine until fuel leak verification is complete

Verification

• Turn ignition key to ON position (do not start) for 5 seconds, then OFF. Repeat this cycle 3-4 times to prime fuel system and build pressure
• Inspect all fuel connections, rail mounting points, and injector bases for any signs of fuel leakage
• Start engine and allow to idle. Monitor fuel rail area for leaks during first 2 minutes of operation
• Check for any fuel odor in engine compartment
• Verify engine runs smoothly with no misfires or rough idle conditions
• Scan for diagnostic trouble codes using OBD-II scanner to confirm no fuel system faults are present
• Rev engine to 2500 RPM briefly and recheck all connections for leaks under increased fuel pressure

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