Fuel Leak Diagnosis - Inside of Engine

FUEL LEAK DIAGNOSIS - INSIDE OF ENGINE

IMPORTANT: If you were directed here from Fuel Return System Diagnosis, go to step 15. This will be performed with the same components disconnected as stated in that test.




1. Disconnect the fuel return line (1) at the engine.
2. Remove the air duct from the air cleaner assembly to the turbo inlet.
3. Remove the air intake pipe.




4. Remove the fuel return rubber hose of the fuel injection pump from the junction block (2). Cap the fitting on the block with a 3/8 inch rubber cap (1) to prevent fuel leakage
5. Install the J23738-A Vacuum Pump at the fuel return pipe.
6. Apply 15 inches Hg of vacuum to the pipe.
^ If the vacuum holds, go to step 23.
^ If the vacuum does not hold, go to step 7.
7. Remove the generator.




8. Disconnect the fuel return line (1) from the right front cylinder head.




9. Install the black hose (1) from the J 45873 on to the each cylinder head return port and install the J23738-A onto the black hose on the right cylinder head.
10. Apply 15 inches Hg of vacuum to the port.
11. Install the J23738-A to the black hose on the left cylinder head return port and apply 15 inches Hg of vacuum.
^ If the vacuum holds on both sides, replace the fuel return line between the cylinder head return ports.
^ If the vacuum does not hold on one or both sides, go to step 12.
12. Perform the lower valve cover removal procedure for the bank(s) that did not hold vacuum. Refer to Valve Rocker Arm Cover Replacement - Lower Right and Valve Rocker Arm Cover Replacement - Lower Left in Engine. Then go to step 13.
13. Connect the fuel return line to the right front cylinder head.

Tighten
Tighten the bolts to 15 Nm (11 lb ft).




14. Install the J42964-1 3/8 Fuel Pipe Shutoff Valve (2) to the fuel return line (1).
15. Install the J35800-A Fuel Injector Cleaner on the J 42964-1 3/8 Fuel Pipe Shutoff Valve port closest to the fuel return line.
16. Ensure that the shutoff valve is closed.
17. Add 10 ounces of diesel fuel and 4 ounces of oil dye to the J 35800-A.
18. Connect the shop air supply to the J35800-A.
19. Adjust the pressure regulator on the J35800-A to 15 psi.
20. Clean the fuel injectors and fuel return lines with brake cleaning solvent and let dry.
21. Open the valve on the bottom of the J 35800-A canister.
22. Inspect for leaks around the fuel injectors and the spill lines with a J28428-E High Intensity Black Light Kit. Then go to step 29.
23. Remove both upper valve covers.
24. Install the fuel injector feed pipes.

Tighten
Tighten the fuel feed pipes to 44 Nm (32 lb ft).

25. Add 8 ounces of oil dye to the fuel tank. On dual tank Systems add the dye to the front, or primary, tank. Refer to Fuel System Description.
26. Start the engine.
27. Increase the fuel pressure to 160 MPa with a scan tool.
28. Inspect for leaks around the fuel injectors with a J28428-E Then go to step 29.
29. Tighten or replace any leaking components or gaskets.
30. Perform the lower valve cover installation procedures as necessary. Refer to Valve Rocker Arm Cover Replacement - Lower Left and Valve Rocker Arm Cover Replacement - Lower Right in Engine 6.6L.