Fuel Pump

Remove and replace the in-tank fuel pump assembly on a 1992 Dodge Viper, accessed by lowering the fuel tank from the vehicle.

Warnings

Tools required

Parts

• Fuel pump module assembly × 1 — Use OEM specification
• Fuel pump module O-ring seal × 1 — Included with pump module or order separately
• Fuel line quick-disconnect O-rings × 2 — Use OEM specification

Preparation

1. Park vehicle on level ground outdoors or in well-ventilated shop with no ignition sources within 50 feet
2. Place fire extinguisher within immediate reach of work area
3. Disconnect negative battery cable and isolate terminal away from battery post
4. Remove fuel filler cap to release any tank pressure
5. Relieve fuel system pressure: Remove fuel pump relay from power distribution center (located in engine bay), attempt to start engine and let it run until it stalls, crank engine for 5 seconds to ensure pressure is relieved
6. Raise vehicle on jack stands at all four corners to working height (minimum 24 inches of clearance under tank area)
7. Verify jack stands are secure and vehicle is stable before working underneath

Procedure

1. 1

   Drain fuel tank
   Position a 5-gallon or larger approved fuel storage container to receive drained fuel. The Viper fuel tank is not equipped with a drain plug, so siphon fuel through the filler neck using an approved manual siphon pump (never by mouth). Drain the tank as completely as practical. Label and store drained fuel in approved containers away from work area. store drained fuel in approved containers away from work area.
   ⚠️Fuel will drain rapidly once plug is removed. Ensure drain pan has adequate capacity and is positioned correctly to avoid spills.
2. 2

   Disconnect fuel filler neck
   Locate the fuel filler neck connection at the tank inlet. Loosen the hose clamp securing the filler neck hose to the tank inlet using a flat-blade screwdriver or appropriate socket. Disconnect the filler neck hose from the tank. Locate and disconnect the vent line(s) from the tank using the same method. There may be residual fuel in these lines; have rags ready to catch drips.
   ⚠Filler neck and vent lines will contain residual fuel. Have absorbent rags ready and dispose of properly.
3. 3

   Disconnect fuel supply and return lines
   Locate the fuel supply and return lines at the front of the fuel tank where they connect to the fuel pump module hard lines. These use quick-disconnect fittings. Using the appropriate size fuel line disconnect tool, press the tool into the quick-disconnect fitting and pull the line straight away from the module connection. Repeat for the second line. Inspect the O-rings inside the quick-disconnect fittings for damage and replace if necessary. Cap the open lines with clean shop rags to prevent contamination.
   ⚠Even with system pressure relieved, residual fuel will drain from disconnected lines. Have rags and drain pan positioned to catch fuel.
4. 4

   Disconnect electrical connector
   Locate the fuel pump module electrical connector on top of or near the fuel tank. Press the release tab(s) on the connector and carefully pull the connector halves apart. Inspect connector terminals for corrosion or damage. Do not allow connector to hang where it can be damaged during tank removal.
5. 5

   Support fuel tank
   Position a transmission jack or use ratchet straps to securely support the fuel tank from underneath. The tank must be firmly supported before loosening any mounting hardware. If using ratchet straps, support the tank with a wide board across the straps to distribute load evenly. Ensure support is stable and tank cannot shift or fall.
   ⚠️Even a partially-filled tank weighs over 100 lbs and can cause severe injury if it falls. Verify support is adequate before proceeding.
6. 6

   Remove tank strap bolts
   Locate the two fuel tank strap bolts at the rear of the tank. Each strap is secured by one bolt on each side. Using the appropriate socket, remove the 2 bolts securing both tank straps. Carefully swing or remove the straps away from the tank. The tank is now supported only by your jack or straps; maintain support at all times.
   Torque spec

   Tank Strap Bolts35 Nm (26 lb-ft)
7. 7

   Lower fuel tank
   Slowly and carefully lower the fuel tank using the transmission jack or by gradually releasing ratchet straps. Lower the tank only enough to access the top of the tank (approximately 6-8 inches). Verify all lines, hoses, and electrical connectors have been disconnected before lowering further. Once access is gained to the fuel pump module on top of the tank, stop lowering. The tank does not need to be fully removed unless pump module cannot be accessed.
   ⚠Lower tank slowly and verify no lines or wires are still connected. Pulling on connected lines can cause fuel leaks or damage.
8. 8

   Clean pump module area
   Using shop rags, thoroughly clean the area around the fuel pump module lock ring and top of the tank. Remove all dirt, debris, and corrosion to prevent contamination from falling into the tank when the module is removed. Any debris entering the tank will damage the new pump.
9. 9

   Remove fuel pump module lock ring
   Using the fuel pump lock ring tool (large spanner type), engage the tool into the notches of the lock ring. Rotate the lock ring counterclockwise to loosen. If the ring is seized, tap the tool with a brass hammer (never steel, which can spark). Once loose, unthread the lock ring completely by hand and remove it. Set aside the lock ring.
   ⚠️Use only brass or non-sparking tools when working inside the fuel tank area. Steel tools can create sparks and ignite fuel vapors.
   Torque spec

   Fuel Pump Module Lock Ring80 Nm (59 lb-ft)
10. 10

    Remove fuel pump module assembly
    Carefully lift the fuel pump module assembly straight up and out of the tank. The module includes the pump, fuel level sender, and pickup strainer. Angle the module as needed to clear the tank opening without bending the fuel level sender float arm. Note the orientation of the module for installation of the new unit. Remove and discard the old O-ring seal from the tank opening.
    ⚠Fuel will drain from the module as it is removed. Have rags and drain pan ready. Do not bend or damage the fuel level sender float arm.
11. 11

    Install new fuel pump module
    Install the new O-ring seal into the groove in the fuel tank opening. Ensure the O-ring is seated properly with no twists or damage. Carefully lower the new fuel pump module into the tank, angling as necessary to clear the opening without damaging the float arm. Ensure the module is oriented correctly (same position as the old unit was removed) and seated fully into the tank opening with the O-ring properly positioned.
    ℹ️Verify the new module orientation matches the original installation position to ensure proper fuel level sender operation and pump pickup alignment.
12. 12

    Install fuel pump module lock ring
    Thread the lock ring onto the fuel pump module by hand, turning clockwise. Once hand-tight, use the fuel pump lock ring tool to tighten the ring to the specified torque. Ensure the lock ring is fully seated and the O-ring has not been pinched or displaced during tightening. Verify the module cannot rotate in the tank.
    Torque spec

    Fuel Pump Module Lock Ring80 Nm (59 lb-ft)
13. 13

    Raise and secure fuel tank
    Using the transmission jack or ratchet straps, carefully raise the fuel tank back into position in the vehicle. Align the tank with the mounting points and ensure all clearances are correct. Guide any wiring or lines to prevent pinching. Once the tank is in position, install both tank straps and secure with the strap bolts. Tighten the strap bolts to the specified torque. Remove the jack or straps used for support.
    Torque spec

    Tank Strap Bolts35 Nm (26 lb-ft)
14. 14

    Reconnect electrical connector and fuel lines
    Reconnect the fuel pump module electrical connector, ensuring it clicks into place and the locking tab engages. Reconnect the fuel supply and return lines to the module hard lines by pushing the quick-disconnect fittings straight onto the connections until they click. Verify both lines are fully seated by attempting to pull them off (they should not release without using the disconnect tool).
15. 15

    Reconnect filler neck and vent lines
    Reconnect the fuel filler neck hose to the tank inlet and secure with the hose clamp, tightening securely. Reconnect the vent line(s) and secure with their clamps. Ensure all connections are tight and properly positioned to prevent kinks or rubbing.

Reassembly

1. Reinstall the fuel pump relay in the power distribution center
2. Reconnect the negative battery cable
3. Leave the fuel filler cap off initially

Verification

• Add 2-3 gallons of fresh fuel to the tank through the filler neck
• Turn the ignition key to the ON position (do not start) and listen for the fuel pump to run for 2-3 seconds, then turn OFF. Repeat this cycle 3-4 times to prime the fuel system
• With the vehicle still raised on jack stands, inspect all fuel line connections, the pump module seal, filler neck, and vent lines for any signs of fuel leakage
• If no leaks are observed, start the engine and let it idle. Monitor for leaks and listen for abnormal fuel pump noise
• Check that the fuel gauge reads correctly (should indicate the amount of fuel added)
• Turn off the engine and perform a final inspection of all connections for leaks
• Install the fuel filler cap
• Lower the vehicle from jack stands
• Test drive the vehicle and verify normal operation with no fuel odors or leaks

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