This procedure covers the removal and replacement of a single fuel injector on the 3.5L EcoBoost V6 engine, including fuel system depressurization and fuel rail service.

Warnings

Tools required

Parts

• Fuel injector × 1 — Use OEM specification
• Fuel injector O-ring kit × 1 — Use OEM specification
• Fuel line fitting O-rings × 2 — Use OEM specification

Preparation

1. Ensure engine is completely cold to touch
2. Park vehicle on level surface and engage parking brake
3. Place wheel chocks at rear wheels
4. Open hood and support with prop rod
5. Disconnect negative battery cable and wait 2 minutes for system power-down
6. Remove engine cover by pulling upward on cover (pull tabs release from grommets)
7. Have fire extinguisher readily accessible in work area
8. Prepare catch container for residual fuel spillage (expect 1-2 ounces)

Procedure

1. 1

   Relieve fuel system pressure
   Locate the Schrader valve on the fuel rail (passenger side of engine). Remove the cap from the valve. Wrap shop towels around the valve to catch fuel spray. Using the fuel pressure gauge with adapter, slowly depress the valve core to release pressure. Allow pressure to bleed down to zero on the gauge. Keep towels in place until all residual fuel stops dripping.
   ⚠️Fuel will spray from valve. Keep face and ignition sources away. Wear safety glasses.
2. 2

   Disconnect fuel supply line
   Locate the fuel supply line connection at the fuel rail (driver side). Use the appropriate size fuel line disconnect tool to release the quick-connect fitting. Slide the tool over the line and push toward the rail while pulling the line away. Place shop towels beneath connection to catch residual fuel. Cap or plug the disconnected line to prevent contamination.
   ⚠Some fuel spillage is normal. Have towels ready and dispose of fuel-soaked materials properly.
3. 3

   Disconnect electrical connectors
   Identify the faulty injector position (cylinders numbered 1-2-3 on passenger side, 4-5-6 on driver side, front to rear). Press the locking tab on the injector electrical connector and pull straight up to disconnect. Move connector aside. If working on multiple injectors, label connectors to ensure correct reinstallation.
   ℹ️Do not pull on wires. Only grasp the connector body to prevent wire damage.
4. 4

   Remove fuel rail mounting bolts
   Locate the four fuel rail mounting bolts (two per rail on this twin-rail system). The rail serving the injector being replaced must be removed. Use 8mm socket to remove the two bolts securing the affected fuel rail. Keep bolts organized for reinstallation. Note bolt locations as they thread into the intake manifold.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
5. 5

   Remove fuel rail assembly
   Carefully lift the fuel rail upward with even pressure. The injectors will pull out of the intake manifold bores with the rail. You may need to gently rock the rail side-to-side while lifting to break the O-ring seal. Lift rail approximately 6 inches and set aside on clean shop towels. Be careful not to damage injector tips or allow debris into injector bores.
   ⚠Do not pry against fuel rail. Aluminum rail can be damaged easily. Use only lifting motion.
6. 6

   Remove faulty fuel injector
   Locate the retaining clip securing the injector to the fuel rail. Use a small flat tool to pry the clip away from the rail and slide it off the injector. With the clip removed, pull the injector straight out of the fuel rail. If injector is stuck, use a fuel injector puller tool or carefully rock the injector while pulling. Remove and discard old O-rings from the injector bores in both the fuel rail and intake manifold.
   ℹ️Note injector orientation before removal. New injector must be installed in same position.
7. 7

   Prepare new fuel injector
   Remove new injector from packaging. Verify part number matches application. Install new O-rings from kit onto the injector - one upper O-ring where injector seats into fuel rail, one lower O-ring where injector seats into manifold. Lightly lubricate both O-rings with clean engine oil or provided lubricant. Do not use petroleum jelly or other incompatible lubricants.
   ⚠Ensure O-rings are properly seated in their grooves before installation. Twisted or pinched O-rings will cause fuel leaks.
8. 8

   Install new fuel injector into rail
   Insert the new injector into the fuel rail socket, aligning the electrical connector orientation to match the original position. Push firmly until the injector seats completely against the rail. Install the retaining clip over the injector, ensuring it clicks into place and fully secures the injector. Tug gently on injector to verify clip is properly engaged.
9. 9

   Inspect and clean injector bores
   Inspect the injector bore in the intake manifold for debris, carbon buildup, or damage. Use a clean lint-free cloth to wipe the bore clean. Do not allow any debris to fall into the cylinder. If old O-ring material remains in bore, carefully remove with pick tool. Install new lower O-ring into intake manifold bore if not already on injector.
   ⚠Cover open intake ports with clean shop towels to prevent debris entry if working on multiple injectors.
10. 10

    Reinstall fuel rail assembly
    Align all injectors with their respective bores in the intake manifold. Ensure each injector is properly oriented with electrical connector facing the correct direction. Push down evenly on the fuel rail until all injectors seat fully into the manifold. You should feel a positive click as each O-ring passes into its bore. Verify rail sits flat and all injectors are fully inserted.
11. 11

    Install fuel rail mounting bolts
    Install the two fuel rail mounting bolts hand-tight. Ensure rail is properly positioned and not cocked to one side. Torque bolts to specification using torque wrench in a cross pattern (alternate between bolts). Do not overtighten as this can crack the aluminum fuel rail or strip threads in the intake manifold.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
12. 12

    Reconnect fuel supply line
    Remove the cap or plug from the fuel supply line. Inspect the quick-connect fitting for damage and verify new O-rings are installed if replacement O-rings were included in parts kit. Push the fuel line fitting straight onto the fuel rail connection until you hear and feel a positive click. Tug on the line to verify it is locked in place.
    ℹ️Line must click audibly into place. If no click is heard, disconnect and reconnect until proper engagement is achieved.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
13. 13

    Reconnect electrical connector
    Push the electrical connector onto the new fuel injector until the locking tab clicks into place. Verify connector is fully seated and locked. Gently pull on connector to confirm retention. Ensure wiring harness is routed properly and not in contact with hot engine components or moving parts.
14. 14

    Reconnect battery and prime fuel system
    Reconnect the negative battery cable. Turn the ignition key to ON position (do not start engine) for 5 seconds, then OFF. Repeat this cycle 3-4 times to prime the fuel system and pressurize the fuel rail. During priming, inspect all fuel connections for leaks. Look carefully at fuel rail bolts, supply line connection, and around the new injector.
    ⚠️If any fuel leaks are observed, immediately turn off ignition, disconnect battery, relieve pressure, and correct the leak before proceeding.

Reassembly

1. Reinstall engine cover by aligning grommets with mounting posts and pressing down firmly until cover clicks into place
2. Verify all tools and materials are removed from engine compartment
3. Wipe up any spilled fuel with shop towels and dispose of properly in sealed container

Verification

• Start engine and allow to idle. Listen for smooth idle with no misfires or rough running
• Observe engine for fuel odor or visible fuel leaks around injector, fuel rail, and supply line
• Check for diagnostic trouble codes using scan tool. No fuel system codes should be present
• Perform a test drive and verify normal acceleration and power delivery with no hesitation
• After test drive, perform final visual inspection of all fuel connections with engine off
• Monitor fuel trims with scan tool if available - long term fuel trims should be within ±10% after several drive cycles

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