Probable Cause
Table 22
Troubleshooting Test Steps Values Results
1. Interview the Operator
A. Ensure the engine starting procedure was followed.
Starting procedures
Result: The engine starting
procedure was incorrectly followed.
Ensure that the engine starting procedure is correctly
followed.
Verify that the problem is resolved.
Result: The engine starting
procedure was correctly followed.
Proceed to Test Step 2.
2. Check the Fuel Shutoff Valve
A. Make sure the fuel shutoff valve is Open. Fuel valve
Result: The manual valve in
the fuel line is closed. Open the valve.
Verify that the problem is resolved.
Result: The manual valve in
the fuel line is open. Proceed to Test Step 3.
3. Check the Fuel Level
A. Check the fuel level. Fuel level
Result: The fuel level is low
in the fuel tank.
Remove the air from the fuel system.
Verify that the problem is resolved.
Result: The fuel level is not
low in the fuel tank. Proceed to Test Step 4.
4. Check the Fuel Quality
A. Check the fuel for contamination. Contamination
Result: The fuel contains
water, dirt, ice, or wax. Replace the fuel filters. Replace the fuel in the fuel tank with clean fuel. Verify that the problem is resolved.
Result: The fuel does not
contain water, dirt, ice, or wax. Proceed to Test Step 5.
5. Check the Engine Crank Speed
A. Check the engine cranking speed. Conditions that cause low cranking speed: 1. The engine oil is too thick.
2. The connections of the battery cables to the starting motor are loose.
Crank Speed
Result: Engine cranking speed
is too slow.
Make the necessary repairs. Verify that the problem is resolved.
Result: Engine cranking speed
is OK.
Proceed to Test Step 6.
6. Check the Engine Glow Plugs
A. Inspect the cable connections and the electrical
Engine Glow Plugs
Result: The glow plugs for the
fuel injection pump do not operate correctly.
connections of the glow plugs and the electrical components of the starting aid circuit. Test the glow plugs for correct operation.
Make the necessary repairs. Verify that the problem is resolved.
Result: The glow plugs for the
fuel injection pump operate correctly.
Proceed to Test Step 7.
7. Check the Fuel Shutoff Solenoid
A. Ensure that the fuel shutoff solenoid operates correctly.
Solenoid
Result: The fuel shutoff
solenoid is not operating correctly.
Replace a fuel shutoff solenoid that is suspect.
Verify that the problem is resolved.
Result: The fuel shutoff
solenoid is operating correctly. Proceed to Test Step 8.
8. Check the Operation of the Fuel Transfer Pump
A. Check the fuel pressure when the engine is cranking. Refer to the Specifications Module, "Fuel Transfer Pump" topic for additional information.
Fuel transfer pump
Result: The operation of the
fuel transfer pump is not correct.
Remove the fuel transfer pump if the fuel pressure is too low. The fuel transfer pump must be repaired or replaced. Verify that the problem is resolved.
Result: The operation of the
fuel transfer pump is correct. Proceed to Test Step 9.
9. Check the Fuel Filter
A. Check the fuel filter and fuel lines for restrictions. Drain any water from the fuel filter.
Fuel filter/fuel lines
Result: The fuel filter or the
fuel lines are restricted. Replace the suspect component.
Verify that the problem is resolved.
Result: The fuel filter or the
fuel lines are not restricted. Proceed to Test Step 10.
10. Check the Timing for the Fuel Injection Pump
A. Check the timing of the fuel injection pump. Adjust the timing or replace the fuel injection pump. Refer to the Specifications Module, "Fuel Injection Pump" topic for additional information.
B. Check the operation of the fuel rack linkage. C. Make sure that the high-pressure fuel lines are connected to the fuel injection nozzles in the correct order.
D. Make sure that the mounting bolts of the fuel injection pump are tightened to the correct torque. Inspect the fuel lines for leaks or for restrictions. The damaged fuel lines or fittings must be repaired or replaced.
Fuel injection pump timing
Result: The operation of the
fuel injection pump is not correct.
The fuel injection pump must be repaired or replaced. Verify that the problem is resolved.
Result: The operation of the
fuel injection pump is correct. Proceed to Test Step 11.
11. Inspect the Fuel Injection Linkage and the Governor
A. Inspect the governor and the fuel injection linkage for damage or the fuel injection linkage for incorrect assembly in the timing gear case.
Governor and fuel injection linkage
Result: There is a problem
with the governor or the fuel injection linkage.
Make the necessary repairs. Verify that the problem is resolved.
with the governor or the fuel injection linkage.
Proceed to Test Step 12.
12. Inspect the Fuel Injection Nozzles
A. Run the engine at the rpm that gives maximum misfiring or rough running. Then, loosen a fuel line nut on the injection line for each cylinder. Loosen one nut at a time. Then, tighten that nut before the next fuel line nut is loosened. If loosening the fuel line nut does not affect the operation of the engine, the fuel injection nozzle is probably suspect. Test the fuel injection nozzle for that cylinder.
B. Make sure that the fuel injection nozzles are properly sealed in the threaded ports. Make sure that the fuel injection nozzles are correctly aligned in the threaded ports. Make sure that the fuel injection nozzles are tightened to the correct torque. Ensure that the gaskets and the seat washers are installed on the fuel injection nozzles correctly. Make sure that the bottom of the threaded ports are clean and free of debris. Make sure that the bottom of the threaded ports do not contain extra gaskets.
Fuel Injection Nozzles
Result: A fuel injection nozzle
is not operating correctly. Replace the suspect fuel injection nozzle.
Make sure that all of the fuel injection nozzles are the correct type for the engine. Test the pressure setting of the fuel injection nozzles. Refer to the Specifications Module, "Fuel Injection Nozzles" topic for additional information. Verify that the problem is resolved.
Result: The fuel injection
nozzles are operating correctly. Proceed to Test Step 13.
13. Check the Cylinder Compression
A. Starting the engine may be difficult in warm weather. The engine may not start in cold weather. Low compression is most frequently caused by the following conditions:
· Piston rings are worn or broken. · The piston height is incorrect. · The piston is damaged.
· The fuel injection nozzles are not seated correctly. · The valve lash requires adjustment.
· The fuel injection pump timing is incorrect. · The engine timing is incorrect.
· When an inlet valve or an exhaust valve is fully
seated, gases leak past the valve head.
Cylinder compression
Result: The cylinders have
low compression.
Make the necessary repairs. Verify that the problem is resolved.