GM Service Manual Online
For 1990-2009 cars only

Important: 

   • If a fuel system problem is caused by contaminated fuel or other foreign material in the fuel tank, the tank must be cleaned. If the tank is rusted or is still contaminated after cleaning, the tank must be replaced.
   • Only use oil-free compressed air to blow out the fuel pipes.
   • Inspect the fuel tank internally and clean the fuel tank if the you find a plugged fuel filter.

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Remove the fuel tank from the vehicle. Refer to Fuel Tank Replacement .
  3. Remove the fuel sender assembly from the fuel tank. Refer to Fuel Sender Assembly Replacement .
  4. Important: When flushing the fuel tank, handle the fuel and water mixture as a hazardous material. Handle the fuel and water mixture in accordance with all applicable local, state, and federal laws and regulations.

  5. Fill the fuel tank with hot water.
  6. Shake the fuel tank vigorously for 5 minutes.
  7. Drain the fuel tank.
  8. Important: If the inside of the fuel tank contains any traces of rust after cleaning, replace the fuel tank.

  9. Inspect that all of the water is removed from the fuel tank.
  10. Install the fuel sender assembly to the fuel tank. Refer to Fuel Sender Assembly Replacement .
  11. Install the fuel tank to the vehicle. Refer to Fuel Tank Replacement .
  12. Refill the fuel tank.
  13. Connect the negative battery cable.
  14. Inspect for fuel leaks and repair as necessary.