This procedure covers removal and replacement of the fuel rail assembly on the 5.0L Coyote V8 engine, including fuel injector service.

Warnings

Tools required

Parts

• Fuel rail assembly (if replacing) × 1 — Use OEM specification
• Fuel injector O-rings × 16 — Use OEM specification
• Fuel line O-rings × 2 — Use OEM specification
• Engine cover grommets (if damaged) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery cable and wait 2 minutes for airbag system to deplete
4. Remove engine cover by pulling upward on all four corners to release grommets
5. Place drain pan under work area to catch fuel spillage

Procedure

1. 1

   Relieve fuel system pressure
   Locate the fuel pressure relief valve on the fuel rail (driver side rail, rear section). Attach fuel pressure gauge with drain hose into container. Slowly open valve to release pressure. Verify pressure drops to zero on gauge before proceeding.
2. 2

   Disconnect main fuel supply line
   Locate the fuel supply line connection at the passenger side fuel rail. Use appropriate size fuel line disconnect tool to depress the locking tabs. Pull line straight out from rail fitting. Have shop towels ready as residual fuel will drain. Cap the line to prevent contamination.
   ⚠Even with pressure relieved, expect fuel spillage from the line. Keep towels and drain pan positioned.
3. 3

   Disconnect fuel return line and injector harnesses
   Disconnect the fuel return line from the driver side fuel rail using the fuel line disconnect tool. Disconnect all eight fuel injector electrical connectors by depressing the locking tab and pulling straight up. Note connector positions for reassembly.
4. 4

   Remove vacuum line and PCV connections
   Disconnect the vacuum line from the fuel pressure regulator on the driver side rail. Disconnect the PCV hose from the valve cover breather. Move hoses out of the way to access fuel rail bolts.
5. 5

   Remove fuel rail mounting bolts
   Remove the four fuel rail mounting bolts (two per rail). The bolts are 8mm and located at the front and rear of each fuel rail. Keep bolts organized as they will be reused unless damaged.
6. 6

   Remove fuel rail assembly
   Carefully pull upward on both fuel rails simultaneously with steady, even pressure. The fuel injectors will pull out of the intake manifold. Rock the rails gently side-to-side if resistance is felt, but do not pry. Once free, lift the entire assembly away from the engine. Keep rails level to prevent damaging injector tips.
   ⚠Injector O-rings may stick in manifold bores. Use gentle rocking motion only - do not use excessive force or pry tools that could damage injectors or manifold.
7. 7

   Inspect and clean injector bores
   Inspect all eight intake manifold injector bores for debris, old O-ring material, or damage. Remove any old O-rings stuck in bores using a pick. Clean bores thoroughly with shop towels. Inspect fuel rail injector mounting points for cracks or damage.
8. 8

   Install new O-rings on fuel injectors
   If reusing injectors, remove and discard all old O-rings (two per injector - upper and lower). Lightly lubricate new O-rings with clean engine oil. Install new O-rings onto each injector, ensuring they seat properly in their grooves. Replace fuel line O-rings on rail fittings.
9. 9

   Install fuel rail assembly
   Position the fuel rail assembly over the intake manifold, aligning all eight injectors with their bores. Apply light downward pressure evenly on both rails, ensuring all injectors seat squarely into the manifold. Push down firmly until rails are flush with mounting surfaces. Verify all injectors are fully seated.
10. 10

    Install and torque fuel rail bolts
    Install all four fuel rail mounting bolts finger-tight. Torque bolts in a criss-cross pattern (front passenger, rear driver, front driver, rear passenger) to specification using a torque wrench.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
11. 11

    Reconnect fuel lines
    Reconnect the fuel supply line to the passenger side rail, pushing firmly until the connector clicks and locks. Reconnect the return line to the driver side rail. Verify both connections are secure by attempting to pull lines away from rails.
    ℹ️Ensure you hear and feel a positive click when fuel lines connect. A partially connected line will leak under pressure.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
12. 12

    Reconnect electrical and vacuum connections
    Reconnect all eight fuel injector electrical connectors, ensuring each clicks into place. Reconnect the vacuum line to the fuel pressure regulator. Reconnect the PCV hose to the valve cover breather.
13. 13

    Reconnect battery and prime fuel system
    Reconnect the negative battery cable. Turn the ignition key to the 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 rails. Check all fuel line connections and injector O-ring areas for leaks.
    ⚠️If any fuel leaks are detected, immediately turn off ignition, relieve fuel pressure, and correct the leak before proceeding.

Reassembly

1. Reinstall engine cover by aligning grommets with mounting posts and pressing down firmly at all four corners until seated
2. Double-check all electrical connectors are fully engaged
3. Verify no tools or shop towels were left in engine compartment

Verification

• Start the engine and allow to idle. Listen for smooth idle with no misfires
• Inspect all fuel rail connections, injector bases, and fuel lines for any signs of fuel leakage while engine is running
• Rev engine to 2000 RPM briefly and recheck for leaks
• Verify no Check Engine Light or fuel system codes are present
• Road test vehicle and confirm normal acceleration and performance with no hesitation or rough running

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