Diesel Fuel System Cleaning Procedure

DIESEL FUEL SYSTEM CLEANING PROCEDURE

CAUTION: Cleanliness cannot be overemphasized when handling or replacing diesel fuel system components. This especially includes the fuel injectors, high-pressure fuel lines and fuel injection pump. Very tight tolerances are used with these parts. Dirt contamination could cause rapid part wear and possible plugging of fuel injector nozzle tip holes. This in turn could lead to possible engine misfire. Always wash/clean any fuel system component thoroughly before disassembly and then air dry. Cap or cover any open part after disassembly. Before assembly, examine each part for dirt, grease or other contaminants and clean if necessary. When installing new parts, lubricate them with clean engine oil or clean diesel fuel only.

NOTE: Do not use any chemical cleaners or solvents on any fuel system lines or metal components. Metal lines, rails and tubes have a coating that will be damaged by these cleaners.

NOTE: Before cleaning the fuel system, perform the Lift Pump Flow test to determine if the Lift Pump was damaged and will require replacement while the Fuel Tank is out of the vehicle. The procedure and specifications can be found in the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Checking The Fuel Delivery System.

1. Remove all of the steel fuel lines from the vehicle.
2. Flush tank to engine compartment bundle lines, supply and return, both directions.
3. Remove the fuel rail and remove the Pressure Limiting Valve (PLV) and pressure switch.
4. Submerge and soak all removed parts in clean diesel fuel.
5. Remove components from the diesel fuel and clean the inside and outside with compressed air.
6. Flush fuel rail with clean diesel and air. Both directions, multiple times.
7. Clean the PLV and pressure switch with compressed air.
8. Remove and flush out the Fuel Tank with clean diesel fuel. Wipe out the inside of the tank with a clean cloth. Use an appropriate fuel container. Dispose of the contaminated fuel using the proper procedures. Fuel Tank - Removal.

CAUTION: Dispose of petroleum based products in a manner consistent with all applicable Local, State, Federal, and Provincial regulations.

9. Inspect the Lift Pump Module screen for extreme dirt accumulation. Clean/flush the Lift Pump Module. Replace if necessary. (Most can be cleaned).
10. Install vent tubes on the rollover valves on the Fuel Tank to prevent water/dirt intrusion.
11. Reinstall the tank and 10 to 15 gallons of clean diesel fuel. Flash any controllers to the latest available software version (PCM/TIPM/CCN). Fuel Tank - Installation.
12. Clean fuel filter housing and install new (latest number available) Mopar Fuel Filter.
13. Pour half a bottle (approximately 15 ounces) of CRC #05232 Diesel Fuel Therapy or equivalent diesel fuel injector cleaner into the Fuel Tank with the clean fuel.
14. Warm engine while checking for leaks or running concerns. Correct concerns as necessary.
15. Drive the truck a short distance (parking lot) and stop several times to agitate the cleaner/fuel mixture in the fuel tank. (Slosh fuel mixture in tank).
16. Monitor the scan tool and validate engine has reached operating temperature of 180°F (82°C).
17. Enable "Injector High Pressure Override" 3 times. This will stress the injectors and High Pressure Delivery Pump and circulate the cleaner/fuel mixture through the entire system.
18. Safely drive truck somewhat aggressively. Perform three times, wide open throttle 0 to 60 hard accelerations in a safe area to circulate cleaner and allow fuel to flush/clean injectors.
19. Verify repair by performing the Diesel After treatment Validation - 6.7L procedure. Testing and Inspection.