Fuel Pump Module

This procedure removes and replaces the fuel pump module assembly in the fuel tank, requiring fuel tank access from beneath the vehicle. Critical safety procedure involving pressurized fuel system.

Warnings

Tools required

Parts

• Fuel pump module assembly × 1 — Use OEM Maserati part number
• Fuel pump lock ring seal × 1 — Included with module or order separately
• Fuel line O-rings (various sizes) × 1 — Use OEM O-ring kit
• Access cover gasket or seal × 1 — Verify if reusable

Preparation

1. Ensure fuel tank is below 1/4 full. If necessary, safely siphon excess fuel into approved storage containers
2. Park vehicle on level surface in well-ventilated area away from ignition sources
3. Place wheel chocks behind front wheels
4. Disconnect negative battery terminal and wait 15 minutes for system capacitors to discharge
5. Raise vehicle on lift or secure jack stands at manufacturer-specified lift points
6. Remove rear seat cushion (pull upward firmly from front edge) to access fuel pump service cover
7. Clean area around fuel pump access cover thoroughly with shop vacuum to prevent debris from entering tank
8. Have drain pan and fuel storage containers ready

Procedure

1. 1

   Relieve fuel system pressure
   With battery disconnected, attach fuel pressure gauge to service port on fuel rail. Open gauge valve slowly to bleed pressure into approved container. Fuel pressure should drop to 0 PSI. If no service port is accessible, proceed knowing pressure exists and be prepared for fuel spillage at line disconnect. Place absorbent pads around work area.
   ⚠️Expect residual pressure even after relieving. Have rags ready to catch fuel spray when disconnecting lines.
2. 2

   Remove fuel pump access cover
   From inside vehicle (rear seat removed), locate the fuel pump access cover in the floor pan under rear seat area. Remove access cover screws using proper torque wrench. Carefully lift access cover and set aside with seal/gasket. Inspect gasket for damage and replace if torn or compressed.
   ⚠Do not allow dirt or debris to fall into fuel tank opening during this or subsequent steps.
   Torque spec

   Access Cover Screws4 Nm (3 lb-ft)
3. 3

   Disconnect electrical connector
   Locate the fuel pump module electrical connector at top of pump assembly. Press release tab and carefully disconnect connector. On some models, connector may have secondary lock that must be released first. Inspect connector terminals for corrosion or damage.
4. 4

   Disconnect fuel supply and return lines
   Using fuel line disconnect tools, release the quick-connect fittings on fuel supply line (larger diameter) and return line (smaller diameter). Press tool onto line, push toward fitting, and pull line away from pump module. Expect fuel spillage - catch in drain pan. Cap open lines immediately with plugs or tape to prevent contamination. For threaded fittings, use proper size wrench to prevent damage to aluminum components.
   ⚠️Fuel will drain from lines. Keep drain pan positioned and have rags ready. Avoid skin contact with gasoline.
   Torque spec

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

   Disconnect evaporative emission lines and breather hoses
   Identify and disconnect any EVAP vapor lines and tank breather hoses connected to pump module top. These may be secured with spring clamps or threaded fittings. Label each line with tape if configuration is unclear for reassembly. Release hose clamps carefully to avoid breaking plastic fittings.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
6. 6

   Remove fuel pump lock ring
   Using Maserati fuel pump lock ring tool (or compatible tool), engage tool tabs into lock ring slots. Strike tool handle sharply with plastic dead-blow hammer in counterclockwise direction to break lock ring free. Once loosened, unscrew lock ring by hand and remove completely. Lock ring is reverse-threaded on some applications - verify direction before applying excessive force. Set lock ring aside and inspect seal/gasket.
   ⚠Do NOT use metal hammer directly on lock ring or use punches that could create sparks near fuel vapors.
   ℹ️Lock ring may be tight due to corrosion. Apply penetrating oil 10 minutes before removal if difficult.
   Torque spec

   Fuel Pump Lock Ring71 Nm (53 lb-ft)
7. 7

   Remove fuel pump module from tank
   Carefully lift fuel pump module straight up and out of fuel tank opening. Module will be heavy with residual fuel. Tilt module slightly to clear tank opening while keeping bottom end over drain pan. Fuel will drain from pump assembly and reservoir sock. Allow fuel to drain completely into pan. Note orientation of module for installation - some modules are indexed and must be installed in specific orientation.
   ⚠Fuel level sender arm extends from module and can bend or break. Lift carefully and avoid contact with tank walls.
   ⚠️Several quarts of fuel will drain from module. Ensure drain pan has adequate capacity.
8. 8

   Inspect tank opening and seal surface
   With pump removed, use flashlight to inspect interior of fuel tank for debris, contamination, or damage. Inspect tank opening seal surface on top of tank for corrosion, dents, or irregularities that would prevent proper seal. Clean seal surface with brass wire brush and solvent if needed - ensure no debris falls into tank. This is the only opportunity to inspect tank interior without full tank removal.
9. 9

   Prepare new fuel pump module
   Remove new fuel pump module from packaging. Compare with old module to verify correct part. Install new O-rings on all fuel line connection points using light coating of clean engine oil for lubrication - do NOT use petroleum jelly. Install new lock ring seal onto pump module flange. Verify float arm moves freely through full range. Check that electrical connector matches original.
   ℹ️Use ONLY new O-rings. Old O-rings will leak under fuel pressure even if they appear undamaged.
10. 10

    Install new fuel pump module
    Carefully lower new pump module into fuel tank opening at correct orientation. Align any indexing tabs or positioning marks. Guide fuel level sender arm carefully to avoid bending. Press module straight down until flange seats completely against tank opening. Module should sit flat with no gaps around seal. Verify seal is positioned correctly and not pinched.
    ⚠Do not force module if resistance is felt. Remove and check for obstructions or incorrect orientation.
11. 11

    Install and torque lock ring
    Place lock ring over pump module and thread clockwise by hand until snug against seal. Using lock ring tool and torque wrench, tighten lock ring to exact specification: 71.0 Nm (53 lb-ft). Apply torque smoothly in clockwise direction. Verify lock ring is fully seated and seal is compressed evenly around entire circumference.
    ⚠️CRITICAL TORQUE: Under-torquing will cause fuel leak and potential fire. Over-torquing can crack pump flange or tank opening. Use calibrated torque wrench.
    Torque spec

    Fuel Pump Lock Ring71 Nm (53 lb-ft)
12. 12

    Reconnect fuel lines
    Connect fuel supply and return lines to pump module fittings. Push quick-connect fittings straight onto module until audible click is heard. Pull back on lines to verify secure connection. For threaded fittings, thread by hand first, then torque to specification using proper wrench. Verify new O-rings are in place before connecting.
    ⚠️CRITICAL CONNECTION: Improperly connected fuel lines will leak under pressure. Verify positive engagement of all quick-connect fittings.
    Torque spec

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

    Reconnect EVAP lines and electrical connector
    Reconnect all evaporative emission lines and breather hoses to correct ports on pump module. Secure hose clamps to specification. Connect electrical connector to pump module - press until secondary lock clicks if equipped. Verify positive connection by gently pulling on connector.
    Torque spec

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

    Install access cover and pressure test
    Install access cover with new or inspected gasket. Torque access cover screws to specification in cross pattern. Reconnect battery negative terminal. Turn ignition key to ON position (do not start engine) for 5 seconds, then OFF. Repeat 3-4 times to prime fuel system and build pressure. Using flashlight, carefully inspect all connections around pump module for fuel seepage or drips. Check fuel lines, lock ring seal, and access cover for leaks.
    ⚠️If ANY fuel leak is detected, immediately disconnect battery and repair leak before proceeding. Do not attempt to start engine with active fuel leak.
    Torque spec

    Access Cover Screws4 Nm (3 lb-ft)
15. 15

    Final inspection and test start
    With no leaks detected, reinstall rear seat cushion. Lower vehicle from lift. Start engine and allow to idle. Monitor fuel pressure gauge if still attached - should read 58-62 PSI at idle. Listen for unusual fuel pump noise. Rev engine gently to 2000 RPM and verify smooth operation. Shut off engine and perform final leak check around all fuel system components accessible from underneath vehicle.

Reassembly

1. Reinstall rear seat cushion by aligning mounting hooks and pressing down firmly until latched
2. Clear any diagnostic trouble codes using scan tool - fuel pump replacement may trigger low pressure or sender circuit codes
3. Properly dispose of old fuel pump module and contaminated fuel according to local environmental regulations
4. Test drive vehicle to verify normal operation - monitor for hesitation, stumbling, or fuel pressure warning lights

Verification

• No fuel leaks detected at pump module lock ring, fuel lines, access cover, or anywhere along fuel system
• Fuel pressure at idle reads 58-62 PSI when measured at fuel rail service port
• Fuel pump operates quietly without excessive whining or buzzing noise
• Engine starts normally and runs smoothly without hesitation or stumbling
• Fuel gauge reads accurately and changes appropriately as fuel is consumed
• No check engine light or fuel system warning lights on instrument cluster
• No fuel odor detected inside vehicle cabin or near fuel tank area after test drive

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