High Pressure Fuel Pump

This procedure covers removal and replacement of the high-pressure fuel pump on the 5.0L Coyote V8 engine, including fuel system depressurization, pump removal, and installation with proper torque specifications.

Warnings

Tools required

Parts

• High-pressure fuel pump assembly × 1 — Ford DG1Z-9350-F or equivalent OEM
• Fuel line O-ring kit × 1 — Use OEM specification
• Fuel pump mounting gasket × 1 — Use OEM specification
• Shop towels × 1 — Generic

Preparation

1. Ensure the engine is completely cold (not run for at least 2 hours)
2. Park vehicle on level ground and apply parking brake
3. Disconnect negative battery cable and wait 5 minutes for system capacitors to discharge
4. Place fire extinguisher within immediate reach of work area
5. Ensure adequate ventilation in work area
6. Place absorbent pads under fuel system work area
7. Remove engine cover by pulling upward on four quick-release fasteners

Procedure

1. 1

   Relieve fuel system pressure
   Locate the fuel pressure relief valve on the fuel rail (driver side, near firewall). Attach fuel pressure gauge to the Schrader valve. Slowly open the valve to bleed pressure into an approved fuel container. Monitor gauge until pressure reads 0 PSI. Close valve and remove gauge. This is critical - residual pressure can exceed 2000 PSI.
   ⚠️Fuel will spray from the pressure relief valve. Keep face and body clear of the valve. Wear safety glasses and chemical-resistant gloves.
2. 2

   Disconnect low-pressure fuel supply line
   Locate the low-pressure fuel supply line entering the high-pressure pump on the driver side of the engine valley. Use the appropriate fuel line disconnect tool to release the quick-connect fitting. Press the tool onto the line and pull the line away from the pump. Place a drain pan beneath to catch residual fuel (expect 4-8 oz spillage).
   ⚠Fuel will drain from the disconnected line. Keep drain pan positioned and have shop towels ready.
3. 3

   Disconnect high-pressure fuel outlet line
   Locate the high-pressure outlet line on top of the pump. This uses a threaded metal fitting. Using a flare nut wrench or line wrench, carefully loosen the fitting. Once loose, unthread by hand and carefully separate the line from the pump. Immediately cap the line opening with a clean shop towel to prevent contamination. Inspect and discard the old O-ring.
   ⚠Use a line wrench to prevent rounding of the fitting. Standard wrenches may damage the soft metal fitting.
   Torque spec

   Fuel Line Fittings25 Nm (18 lb-ft)
4. 4

   Disconnect vacuum line from fuel pressure regulator
   Locate the vacuum line connected to the fuel pressure regulator on the pump body. Press the release tab on the quick-connect fitting and pull the vacuum line straight off. On some models this may be a hose clamp connection - if so, use pliers to slide the clamp back and twist the hose while pulling to remove.
   Torque spec

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

   Disconnect electrical connector
   Locate the electrical connector on the side of the high-pressure fuel pump. Press down on the red safety tab to unlock it, then press the release tab while pulling the connector straight away from the pump. Do not pull on wires - pull only on the connector body.
   ℹ️The connector may be tight due to O-ring seal. Wiggle gently while pulling if needed.
6. 6

   Remove pump mounting bolts
   The high-pressure fuel pump is secured by three mounting bolts in a triangular pattern. Using a socket and ratchet, remove all three bolts completely. Keep bolts organized as they may be of different lengths. Note the position of any ground straps or brackets attached to these bolts.
   Torque spec

   Pump Mounting16 Nm (12 lb-ft)
7. 7

   Remove fuel pump assembly
   Carefully pull the pump assembly straight up and out of the mounting bore. The pump has a camshaft-driven lobe follower on the bottom - withdraw slowly to avoid damaging the cam lobe or dropping the follower. Place the old pump on shop towels in the drain pan as residual fuel will drain out. Retrieve the lobe follower if it remained in the bore.
   ⚠Do not allow the lobe follower to fall into the engine. If dropped, it must be retrieved immediately to prevent catastrophic engine damage.
8. 8

   Inspect and clean mounting area
   Remove and discard the old mounting gasket. Inspect the pump mounting bore for debris, fuel residue, or metal shavings. Clean thoroughly with shop towels. Inspect the camshaft lobe for scoring or wear - it should be smooth and shiny. Check the lobe follower for wear, cracks, or flat spots. Replace if any damage is visible.
   ⚠Do not allow any debris to fall into the engine through the pump mounting bore. Cover the opening with a clean shop towel when not actively working.
9. 9

   Prepare new fuel pump
   Remove the new pump from packaging. Verify it matches the old pump. Install new O-rings on the high-pressure outlet port and low-pressure inlet port - lubricate O-rings lightly with clean engine oil. Ensure the lobe follower is properly seated in the pump drive mechanism. Install the new mounting gasket on the pump flange.
   ℹ️Do not use petroleum jelly or grease on O-rings - use only clean engine oil for lubrication.
   Torque spec

   Fuel Line Fittings25 Nm (18 lb-ft)
10. 10

    Install fuel pump assembly
    Carefully lower the new pump assembly into the mounting bore, aligning the lobe follower with the camshaft drive lobe. The pump will only fit in one orientation due to the bolt hole pattern. Press down firmly to seat the gasket. If the lobe follower was removed, install it on the cam lobe first, then install the pump over it.
    ⚠Ensure the lobe follower is properly aligned with the cam lobe. Misalignment will cause immediate pump failure and potential engine damage.
11. 11

    Install pump mounting bolts
    Install all three mounting bolts finger-tight first to ensure proper alignment. Tighten bolts in a star pattern (alternating across the pump) to specified torque. Use a torque wrench and tighten to exactly 16 Nm (12 lb-ft). Recheck all three bolts to ensure even torque.
    Torque spec

    Pump Mounting16 Nm (12 lb-ft)
12. 12

    Reconnect high-pressure fuel line
    Align the high-pressure fuel line to the pump outlet fitting. Thread the fitting by hand several turns to ensure proper engagement and prevent cross-threading. Once hand-tight, use a line wrench to tighten to specified torque of 34 Nm (25 lb-ft). Do not overtighten as this can damage the fitting or O-ring.
    Torque spec

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

    Reconnect low-pressure fuel supply and vacuum lines
    Push the low-pressure fuel supply line quick-connect fitting onto the pump inlet until it clicks into place. Tug gently to verify it is locked. Reconnect the vacuum line to the fuel pressure regulator - push until seated and verify the locking tab engages. If using a hose clamp, position clamp 1/4 inch from hose end and tighten to 3 Nm (2 lb-ft).
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
14. 14

    Reconnect electrical connector
    Align the electrical connector with the pump connector and push firmly until it clicks. Press the red safety lock tab down until it locks in place. Verify the connection is secure by gently pulling on the connector body.
15. 15

    Prime fuel system and check for leaks
    Reconnect the negative battery cable. Without starting the engine, turn the ignition key to RUN position (not START) for 5 seconds, then OFF. Repeat this cycle 5 times to allow the fuel pump to prime the system. Carefully inspect all fuel connections for leaks while the system is pressurized. Look for wet spots, drips, or fuel odor. If any leaks are found, immediately relieve fuel pressure and correct the issue before proceeding.
    ⚠️Do not attempt to start the engine if any fuel leaks are present. Even small leaks can cause fires once the engine is running.

Reassembly

1. Reinstall engine cover by aligning four quick-release fasteners and pressing firmly until they click
2. Clean up any spilled fuel with absorbent materials and dispose of properly
3. Remove all tools and materials from engine compartment

Verification

• Start the engine and allow it to idle for 2 minutes. Listen for unusual noises from the fuel pump area - it should be nearly silent
• Check fuel pressure with scan tool or fuel pressure gauge - should read 50-65 PSI at idle for 5.0L Coyote engine
• Perform a final visual inspection of all fuel connections for leaks with engine running
• Rev engine to 2000 RPM briefly and verify smooth operation with no hesitation or fuel smell
• Test drive vehicle and verify normal acceleration and no fuel odor in cabin
• After test drive, perform final cold inspection of all connections for seepage or wetness

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