Fuel Injectors - All

Complete replacement of all eight fuel injectors on the 5.0L Coyote V8 engine, including fuel rail removal and fuel system depressurization.

Warnings

Tools required

Parts

• Fuel injector × 8 — Use OEM Motorcraft CM5229 or equivalent
• Fuel injector O-ring kit × 1 — Upper and lower O-rings for all injectors
• Fuel rail O-ring set × 1 — Use OEM specification
• Fuel line O-rings × 2 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure engine is completely cool (minimum 2 hours after last operation)
3. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
4. Remove engine cover by pulling upward on cover; it is retained by grommets on ball studs
5. Place shop towels and drain pan under fuel rail area to catch residual fuel
6. Relieve fuel system pressure: locate fuel pressure relief valve on fuel rail, attach fuel pressure gauge with Schrader adapter, slowly open valve to bleed pressure into approved container
7. Remove fuel pump fuse (F14 in engine compartment fuse box) and attempt to start engine to burn off remaining fuel in rails (engine will not start)

Procedure

1. 1

   Disconnect throttle body and vacuum lines
   Disconnect the throttle body electrical connector by pressing the release tab. Remove the vacuum line from the fuel pressure regulator on the passenger side fuel rail. Disconnect the PCV hose from the rear of the intake manifold. Label all vacuum connections with tape for reassembly reference.
2. 2

   Remove air intake assembly
   Loosen hose clamp at throttle body using 8mm socket. Disconnect mass airflow sensor electrical connector. Remove air filter housing bolts and remove entire intake tube and housing assembly to provide access to fuel rails. Set aside in clean area.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
3. 3

   Disconnect fuel supply line
   Locate the fuel supply line connection at the front of the driver side fuel rail. Using the appropriate fuel line disconnect tool, press the release tabs and pull the line straight off the rail fitting. Have shop towels ready to catch residual fuel (approximately 1-2 oz may drain). Inspect the line connection for damage.
   ⚠Even with system depressurized, residual fuel will spray when line is disconnected. Keep face and ignition sources away from connection point.
4. 4

   Disconnect fuel injector electrical connectors
   Working from front to back on both sides, disconnect all eight fuel injector electrical connectors by sliding the red lock tab up, then pressing the release tab while pulling the connector straight up off the injector. Do not pull on wires. Note the routing of the harness for reassembly.
5. 5

   Remove fuel rail mounting bolts
   Using a 10mm socket, remove the four fuel rail mounting bolts (two per rail). Driver side bolts are located near cylinders 1 and 4; passenger side bolts are near cylinders 2 and 3. Keep bolts organized by side. Note that rails are still retained by injectors in the intake manifold.
   Torque spec

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

   Remove driver side fuel rail and injectors
   Carefully work the driver side fuel rail upward, pulling evenly to extract all four injectors from their bores simultaneously. Use gentle rocking motion if needed, but do not pry against intake manifold. Once free, lift rail with injectors attached and place on clean shop towels. Immediately cover intake manifold injector ports with clean towels to prevent debris entry.
   ⚠Do not allow any debris, dirt, or foreign material to enter the open intake manifold injector bores. Contamination will cause engine damage.
7. 7

   Remove passenger side fuel rail and injectors
   Disconnect the crossover fuel line connecting the two rails by using fuel line disconnect tool on the spring-lock coupling. Repeat the removal process for the passenger side fuel rail, extracting all four injectors simultaneously. Cover the intake manifold injector ports immediately with clean towels.
8. 8

   Remove injectors from fuel rails
   With rails on clean work surface, remove the metal retaining clip from each injector by prying up with a small flat-blade screwdriver. Twist and pull each injector out of the fuel rail cup. Inspect fuel rail cups for debris or damage. Note the orientation of each injector's electrical connector for reference during installation.
9. 9

   Clean injector bores and inspect
   Remove towels from intake manifold one port at a time. Using a clean shop towel, wipe each injector bore to remove any carbon buildup or old O-ring residue. Inspect each bore for damage or cracks. Use wire brush if needed to clean intake manifold mating surface around bores, then re-cover ports when finished. Clean fuel rail cups with shop towels.
10. 10

    Prepare new injectors with O-rings
    Lubricate all new O-rings with clean engine oil or provided lubricant. Install new upper and lower O-rings on each of the eight new fuel injectors, ensuring they are seated properly in their grooves without twisting. Install new O-rings on fuel rail cups if provided in kit. Lubricate O-rings again after installation.
11. 11

    Install injectors into fuel rails
    Insert each new injector into its corresponding fuel rail cup, orienting the electrical connector in the same position as original injectors (connectors should face outboard). Push injector firmly until it bottoms in the cup. Install the metal retaining clip on each injector, ensuring it fully engages the injector body and rail cup. Verify each clip is secure by attempting to pull injector out.
12. 12

    Install fuel rails with injectors
    Remove protective coverings from intake manifold ports one rail at a time. Align all four injectors on driver side rail with their corresponding bores. Push down evenly on the rail to seat all injectors simultaneously, using gentle rocking motion if needed. Do not force. Repeat for passenger side rail. Reconnect crossover fuel line between rails using new O-rings and ensuring spring-lock coupling clicks into place.
    Torque spec

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

    Secure fuel rails and torque bolts
    Install the four fuel rail mounting bolts finger-tight, ensuring rails are fully seated and injectors are bottomed in their bores. Using torque wrench, torque all four fuel rail bolts to specification in a cross pattern (driver front, passenger rear, passenger front, driver rear) to ensure even seating.
    Torque spec

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

    Reconnect fuel supply and electrical connections
    Install new O-rings on fuel supply line fitting. Push fuel supply line onto rail fitting until it clicks and locks into place. Tug on line to verify secure connection. Reconnect all eight fuel injector electrical connectors, ensuring they click into place and red lock tabs are pressed down fully. Verify correct routing of injector harness.
    Torque spec

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

    Reinstall intake system and test
    Reconnect all vacuum lines, PCV hose, and throttle body connector to their original positions. Reinstall air intake assembly and tighten throttle body hose clamp to specification. Reconnect negative battery cable. Turn ignition to ON position (do not start) for 5 seconds, then OFF. Repeat 3 times to prime fuel system. Inspect all fuel connections for leaks. Start engine and inspect again while running. Check for smooth idle and proper operation.
    ⚠Inspect all fuel connections carefully for leaks during initial prime cycle and startup. Any leak presents immediate fire hazard.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)

Reassembly

1. Reinstall engine cover by aligning grommets with ball studs and pressing down firmly until seated
2. Reinstall fuel pump fuse F14 in engine compartment fuse box
3. Clear any diagnostic trouble codes using OBD-II scanner
4. Allow engine to reach operating temperature and verify no fuel odors or visible leaks

Verification

• Verify engine starts normally and idles smoothly without misfires or rough running
• Check for fuel leaks at all connection points with engine running and at operating temperature
• Verify no fuel odor in engine compartment or cab
• Confirm all fuel injector electrical connectors are fully seated with lock tabs engaged
• Road test vehicle and verify normal acceleration, power delivery, and fuel economy
• Scan for diagnostic trouble codes; address any fuel trim or misfire codes that appear
• Verify fuel pressure is within specification (55-65 PSI at idle) using fuel pressure gauge if available

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