Fuel Injectors - All

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

Warnings

Tools required

Parts

• Fuel injector × 6 — Motorcraft CM-5228 or equivalent
• Fuel injector O-ring kit × 1 — Upper and lower O-rings for 3.5L EcoBoost
• Fuel line O-rings × 2 — Use OEM specification

Preparation

1. Ensure engine is completely cool
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable and wait 2 minutes for system discharge
4. Remove engine cover by pulling upward on cover - it is retained by grommets only
5. Place shop towels around work area to catch fuel spillage
6. Have drain pan ready for fuel collection

Procedure

1. 1

   Relieve fuel system pressure
   Locate the fuel rail Schrader valve on the driver side fuel rail. Attach fuel pressure gauge to the valve. Open the valve slowly to bleed pressure into a suitable container. Confirm pressure drops to 0 PSI before proceeding. Remove gauge and cap the Schrader valve.
2. 2

   Disconnect fuel supply line
   Locate the fuel supply line connection at the passenger side fuel rail. Use the appropriate fuel line disconnect tool to release the spring lock coupling. Pull the line straight back to disconnect. Cap or plug the line to prevent contamination. Inspect O-rings and replace if damaged.
   ⚠Residual fuel will drain from the line. Have shop towels ready.
3. 3

   Disconnect electrical connectors
   Press the release tab on each fuel injector electrical connector and pull straight up to disconnect. There are three injectors per bank (six total). Label connectors if desired to ensure correct reassembly, though connectors are keyed.
4. 4

   Disconnect vacuum lines and PCV hose
   Disconnect the brake booster vacuum line from the intake manifold if it interferes with access. Disconnect the PCV hose from the driver side valve cover. Use pliers to compress and slide hose clamps away from connections before pulling hoses free.
   Torque spec

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

   Remove fuel rail bolts
   Remove the four fuel rail mounting bolts - two per rail. Bolts are 8mm and located at the ends of each fuel rail. Keep bolts organized for reinstallation.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
6. 6

   Remove fuel rails with injectors
   Carefully pull upward on both fuel rails simultaneously to extract injectors from the intake manifold. Rock rails gently side-to-side if they resist removal. Once free, lift the entire fuel rail assembly (both rails with crossover tube and all injectors attached) from the engine bay.
   ⚠Fuel will drain from injectors. Keep drain pan positioned under the rails.
7. 7

   Remove injectors from fuel rails
   With fuel rail assembly on clean work surface, use pick tool to release the metal retaining clip on each injector. Slide clip off the injector. Pull injector straight out of fuel rail while twisting gently. Remove and discard upper and lower O-rings from each injector.
8. 8

   Prepare new injectors
   Lubricate new upper and lower O-rings with clean engine oil or fuel. Install new O-rings onto each new injector, ensuring they seat properly in their grooves. Do not use petroleum jelly or silicone lubricants.
9. 9

   Install injectors into fuel rails
   Insert each new injector into the fuel rail with a gentle twisting motion until it bottoms out. Install the metal retaining clip by sliding it over the injector until it clicks into place. Verify each clip is fully seated and the injector cannot be pulled free.
10. 10

    Clean intake manifold injector bores
    Inspect each injector bore in the intake manifold. Remove old O-ring material and debris using a clean shop towel. Do not allow any debris to fall into the intake ports. Ensure bores are clean and dry.
    ⚠Do not scratch or damage the injector bore surfaces.
11. 11

    Install fuel rail assembly
    Position fuel rail assembly over the intake manifold, aligning all six injectors with their bores. Press down firmly and evenly on both rails simultaneously until injectors are fully seated in the manifold. All injectors must be completely inserted before installing bolts.
12. 12

    Install fuel rail bolts
    Install all four fuel rail mounting bolts finger-tight, then torque in a cross pattern to specification using a torque wrench. Verify rails are seated flat against mounting surfaces.
    Torque spec

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

    Reconnect fuel supply line
    Install new O-rings on the fuel supply line if not already done. Push the fuel line straight into the fuel rail coupling until it clicks. Pull back on the line to verify it is locked in place.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
14. 14

    Reconnect electrical and vacuum connections
    Reconnect all six fuel injector electrical connectors by pushing down until they click. Reconnect PCV hose and brake booster vacuum line. Reinstall and tighten hose clamps to specification.
    Torque spec

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

    Prime fuel system and check for leaks
    Reconnect negative battery cable. Turn ignition to ON position (do not start) for 5 seconds, then OFF for 10 seconds. Repeat this cycle 3-4 times to prime the fuel system. Inspect all fuel connections for leaks. Start engine and allow to idle while monitoring for fuel leaks and rough running. Check for diagnostic trouble codes.
    ⚠️If any fuel leaks are detected, immediately shut off engine and repair leak before continuing.

Reassembly

1. Reinstall engine cover by aligning grommets and pressing down firmly until it seats
2. Clear any diagnostic trouble codes that may have set during the procedure
3. Verify engine runs smoothly at idle and under acceleration

Verification

• Start engine and verify smooth idle with no misfires or rough running
• Inspect all fuel connections for leaks while engine is running
• Rev engine to 2000-3000 RPM and verify smooth operation
• Scan for diagnostic trouble codes - there should be none related to fuel injectors
• Test drive vehicle to verify normal performance and no check engine light

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