Probable Causes
- Event codes
- Throttle signal
- Injection actuation pressure
- Fuel supply
Recommended Actions
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.
Event Codes
Certain event codes may cause poor performance. Connect Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.
Throttle Signal
Monitor the status for "Throttle Position" on Cat ET. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed. Refer to Troubleshooting, "Speed Control - Test".
Injection Actuation Pressure
- Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level.
- If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to ensure that the air has been purged from the injection actuation pressure circuit.
- Compare the actual actuation pressure and the desired actuation pressure on Cat ET. If these readings do not agree within 2000 kPa (290 psi), refer to Troubleshooting, "Injection Actuation Pressure - Test".
Fuel Supply
- Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
- Check the fuel tank for foreign objects which may block the fuel supply.
- Prime the fuel system if any of the following procedures have been performed:
- Replacement of the fuel filters
- Service on the low pressure fuel supply circuit
- Replacement of unit injectors
Note: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel.
- Replacement of the fuel filters
- Check the fuel pressure after the fuel filter while the engine is being cranked. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling and fuel pressure regulating valve.
| NOTICE |
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Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again. |