Fuel Injector - Single

This procedure covers the removal and replacement of a single fuel injector on the 5.0L Coyote V8 engine, including fuel pressure relief and fuel rail removal.

Warnings

Tools required

Parts

• Fuel injector × 1 — Motorcraft CM-5319 or equivalent
• Fuel injector O-ring kit × 1 — Upper and lower O-rings for Coyote injector
• Fuel rail O-rings × 2 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable and wait 2 minutes for system capacitors to discharge
4. Place fender covers to protect paint from fuel contact
5. Have fire extinguisher readily accessible
6. Identify which cylinder injector requires replacement (cylinder numbering: passenger side front to rear 1-2-3-4, driver side front to rear 5-6-7-8)

Procedure

1. 1

   Relieve fuel system pressure
   Locate the fuel pressure test port on the fuel rail. Remove the cap and attach a fuel pressure gauge with a drain hose leading into an approved fuel container. Open the gauge valve to slowly release fuel pressure until gauge reads zero. Remove gauge and reinstall cap on test port. Have shop towels ready to catch residual fuel.
2. 2

   Remove engine cover
   Remove the plastic engine cover by pulling upward on the cover to disengage the grommets from the mounting posts. The cover is not bolted and should lift off with firm upward pressure. Set aside in a clean area.
   Torque spec

   Cover Screws14 Nm (10 lb-ft)
3. 3

   Disconnect electrical connectors
   Locate the fuel injector electrical connectors on the fuel rail. Press down on the connector lock tab and slide the connector off the injector. For the specific injector being replaced, carefully disconnect it. If removing an entire fuel rail section, disconnect all injectors on that bank. Also disconnect the fuel rail pressure sensor connector if present on the working side.
4. 4

   Disconnect fuel supply line
   Locate the fuel supply line connection at the fuel rail. Use the appropriate fuel line disconnect tool to release the quick-connect fitting. Push the tool onto the line around the fitting and pull the line away from the rail. Place shop towels beneath the connection to catch fuel spillage. Plug the open line with a clean rag to prevent contamination.
   Torque spec

   Fuel Line Fittings25 Nm (18 lb-ft)
5. 5

   Remove vacuum lines and brackets
   Disconnect any vacuum lines attached to the fuel rail or intake manifold that obstruct access. On the 2015-2020 F-150 5.0L, the PCV hose and any brake booster vacuum lines may need to be moved aside. Label connections if necessary for reassembly. Remove any wire harness brackets or clips attached to the fuel rail mounting bolts.
6. 6

   Remove fuel rail mounting bolts
   Remove the four fuel rail mounting bolts (two per bank if working on one side) using a 8mm socket. The bolts secure the fuel rail to the intake manifold. Keep bolts organized for reinstallation. Note that the fuel rail may be under slight spring tension from the injector O-rings.
   Torque spec

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

   Remove fuel rail assembly
   Carefully pull the fuel rail straight upward with even pressure to disengage all injectors from their bores in the intake manifold. The injectors are held by O-ring friction. Rock the rail gently side-to-side while pulling up if needed, but avoid cocking the rail at an angle. Once free, lift the rail with injectors still attached and set on a clean work surface. Be careful not to damage injector tips.
8. 8

   Remove faulty injector from fuel rail
   Locate the specific injector to be replaced. Using needle nose pliers or a small flathead screwdriver, carefully pry or pull the metal retaining clip off the injector at the fuel rail connection. Once the clip is removed, twist and pull the injector straight out of the fuel rail socket. Note the orientation of the injector connector for reinstallation.
9. 9

   Install new injector O-rings
   Remove the old upper and lower O-rings from the new injector (or inspect if reusing injector for testing). Lubricate new O-rings lightly with clean engine oil or provided lubricant. Install the upper O-ring into the groove on the injector body near the fuel inlet, and the lower O-ring into the groove near the injector tip. Ensure O-rings are fully seated in their grooves without twisting.
10. 10

    Install new injector into fuel rail
    Align the new injector with the fuel rail socket, ensuring the electrical connector faces the correct direction to match other injectors. Push the injector firmly into the fuel rail until it seats completely. Install the metal retaining clip by pressing it over the injector body until it clicks into place, securing the injector to the rail.
11. 11

    Inspect and replace fuel rail O-rings
    Inspect the fuel line connection O-rings on the fuel rail. If damaged, worn, or compressed, replace with new O-rings. Lubricate O-rings lightly with clean engine oil. Also inspect the injector bore O-rings in the intake manifold; if any are damaged or remain stuck to the old injector, carefully remove and replace them.
12. 12

    Reinstall fuel rail assembly
    Carefully align all injectors with their corresponding bores in the intake manifold. Ensure injectors are oriented correctly with electrical connectors accessible. Press the fuel rail down evenly with firm pressure until all injectors seat fully into their bores. The rail should sit flush against the mounting surface.
    Torque spec

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

    Install fuel rail mounting bolts
    Install the four fuel rail mounting bolts by hand, ensuring they thread smoothly. Tighten bolts in a cross pattern to 12.0 Nm (9.0 lb-ft) using a torque wrench. Do not over-tighten as this can damage the plastic fuel rail or crack the intake manifold bosses.
    Torque spec

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

    Reconnect fuel line and electrical connections
    Push the fuel supply line quick-connect fitting onto the fuel rail inlet until it clicks into place. Tug gently to verify it is locked. Reconnect all injector electrical connectors by pressing them onto the injectors until they click. Reconnect the fuel rail pressure sensor connector if disconnected. Reinstall any vacuum lines and wire harness brackets removed earlier.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
15. 15

    Reinstall engine cover and reconnect battery
    Align the engine cover with the mounting posts and press down firmly until all grommets engage. Reconnect the negative battery cable. Ensure all tools and materials are clear of the engine compartment.

Reassembly

1. Double-check all electrical connectors are fully seated and locked
2. Verify fuel line quick-connect is properly engaged
3. Ensure no tools or shop towels are left in engine bay
4. Confirm all vacuum lines are reconnected to their original positions

Verification

• Turn ignition key to ON position (do not start) and listen for fuel pump priming for 2-3 seconds. Cycle key off and on three times to build fuel pressure
• Inspect all fuel connections for leaks, particularly at the fuel rail supply line and around the replaced injector
• Start engine and allow to idle. Check for fuel odor or visible leaks around fuel rail and injectors
• Monitor engine operation for smooth idle and proper running condition. Check for diagnostic trouble codes using an OBD-II scanner
• Test drive vehicle and verify normal acceleration and no misfires. Clear any adaptive fuel trim values if necessary using scan tool

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