Fuel System Cleaning

Tools Required: SA9127E  Fuel Flow/Pressure Test Adapter

After it is determined that the fuel system is contaminated, using the following procedure to clean is recommended:

1. Place the vehicle on the hoist and open the hood.
Fig 1: Identifying Proper Lift Points
Courtesy of GENERAL MOTORS CORP.
CAUTION: Do not allow smoking or the use of open flames in the area where work on the fuel or EVAP system is taking place. Anytime work is being done on the fuel system, disconnect the negative battery cable, except for those tests where battery voltage is required.
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical.
3. Drain the fuel tank. Refer to Fuel Tank Draining Procedure .
4. Remove the fuel tank. Refer to Fuel Tank Replacement .
5. Disconnect the fuel feed and return line at the fuel rail.
Fig 2: Disconnecting Underhood EVAP Canister Purge Line Near Top Of Passenger Side Strut Tower In Engine Compartment
Courtesy of GENERAL MOTORS CORP.
6. With compressed air, blow out the fuel feed and return lines. Catch the fuel in a container at the opposite end of the line.
7. Remove the EVAP canister from the fuel tank. Refer to Evaporative Emission (EVAP) Canister Replacement .
8. Remove the pump module. Refer to Fuel Pump Module Removal in this section.
Fig 3: Removing & Installing Fuel Pump Module
Courtesy of GENERAL MOTORS CORP.
9. Inspect the inlet filter on the pump. If plugged or damaged, the fuel pump module must be replaced, not serviced separately.
10. Flush the tank with hot water for at least 6 minutes, invert, and drain. All metal chips/debris must be removed from the tank prior to installation.
11. Install the EVAP canister to the fuel tank.
12. Install the fuel pump module to the fuel tank using the new fuel pump seal. Do not connect the fuel feed line to the new filter.
13. Install the fuel tank to the vehicle.
NOTE: Replace plastic fuel line retainers whenever the fuel supply or return line is disconnected at the fuel rail. Install the new retainer into the female cavity of the connection. Care must be taken to ensure that the locking tab is centered in the window of the female cavity. Firmly press the female connection onto the male end until a click is heard, then pull back to confirm engagement. Pinched, kinked, or damaged fuel lines must be replaced.
14. Connect the fuel lines to the fuel rail.
15. Put at least 22.7 liters (6 gallons) of clean fuel into the fuel tank.
16. Connect the negative battery cable. Tighten:  Tighten the battery terminal bolts to 17 N.m (13 lb ft).
17. Connect the scan tool to the vehicle and turn the ignition ON.
18. Raise the vehicle on a hoist and install the male quick connect adapter from the SA9127E  into the fuel feed line.
19. Install the drain hose to the adapter and place the other end in an approved container.
Fig 4: Installing Quick Connect Fitting & Drain Hose To Fuel Feed Line
Courtesy of GENERAL MOTORS CORP.
20. Energize the fuel pump with the scan tool for 1-2 minutes. Refer to Fuel System Diagnosis . This will pump about 1.9 liters (2 quarts) of fuel and purge any debris in fuel pump.
21. Disconnect the fuel drain hose adapter at the fuel feed line and connect the fuel line to the fuel filter.
22. Energize the fuel pump and inspect all connections for leaks.
23. De-energize the pump, lower the vehicle, and start the engine.