Probable Causes
- Diagnostic codes
- Fuel level
- Oil level
- Starting aids
- Shutdown switch
- Direct Fuel Control
- Electrical connectors
- Circuit breakers
- Personality Module
- Engine speed/timing
- Injection actuation pressure
- Unit injectors
- Fuel supply
- Combustion
Recommended Actions
Diagnostic Codes
Certain diagnostic codes may prevent the engine from starting. Connect the Caterpillar Electronic Technician (Cat ET) and check for active diagnostic codes. Troubleshoot any codes that are present before continuing with this procedure.
Fuel Level
Visually check the fuel level. Do not rely on the fuel gauge only. If necessary, add fuel.
Oil Level
Check the engine oil level. If necessary, add oil.
Note: Engine oil supplies the injection actuation pressure circuit. Proper engine oil level is necessary for fuel injection.
Starting Aids
- If cold ambient conditions exist, check operation of starting aids. Replace the ether canister if the ether is low.
- Ensure the proper operation of the jacket water heater. Repair the jacket water heater and/or replace the jacket water heater, if necessary.
- Check for presence of solidified fuel (wax).
Engine Shutdown Switch
The engine shutdown switches should be in the OFF position. Use Cat ET to verify the status of the shutdown switches. When a shutdown occurs, the keyswitch must be turned to the OFF position for at least 15 seconds before restarting the engine.
Note: If Cat ET will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Will Not Communicate With ECM".
Direct Fuel Control
The direct fuel control uses an external governor to govern the engine. Make sure that the governor is turned on. If the governor is turned on, make sure that the ECM is receiving a PWM signal. Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for more information.
Electrical Connectors
Check for correct installation of the following connectors: the J1/P1 and the J2/P2 ECM connectors, the J20/P20 and the J44/P44 Engine speed/timing sensor connectors and the unit injector connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Circuit Breakers
Check the circuit breakers and/or fuses on the engine. The circuit protection may exceed the trip point due to overheating. Reset the circuit breakers if the circuit breakers are tripped. Replace any blown fuses.
Personality Module
Verify that the correct personality module is installed in the ECM.
Note: If a new ECM has been installed, the ECM will need to be programmed before the engine will run. Also, the ECM will not communicate with Cat ET if the ECM has not been programmed.
Engine Speed/Timing
- Crank the engine and observe the engine speed onthe status screen on Cat ET. If Cat ET indicates 0 rpm, refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test".
- Ensure that the timing reference gear is installed correctly. The engine will not start if the gear was installed backward. Check for proper orientation between the crankshaft and camshaft drive gears. Correct the orientation and/or replace the drive gear, if necessary. Refer to Disassembly and Assembly, "Camshaft - Remove and Install".
Injection Actuation Pressure
- Crank the engine while you observe the injection actuation pressure on the status screen. If the injection actuation pressure is at least 5000 kPa (725 psi), the problem is not in the injection actuation pressure control system.
- Check the seals on the injection actuation pressure control valve. If the seals are faulty, replace the seals and repeat Step 1.
- Check the wiring harness to the injection actuation pressure control valve for opens and/or shorts.
- Measure the coil resistance on the injection actuation pressure control valve. If the coil resistance is not within 10 ± 5 Ohms, replace the injection actuation pressure control valve.
- If the injection actuation pressure during cranking is less than 5000 kPa (725 psi), the high pressure oil supply circuit may have a leak.
- Unplug the injection actuation pressure control valve and the unit injector connectors.
- Disable the unit injectors with Cat ET and/or the engine shutdown switch.
- Remove the valve mechanism covers.
- Crank the engine while you check the drain holes in the unit injector adapter and the jumper block seals for leaks.
- Repair any leaks and repeat Step 1.
- If the injection actuation pressure during cranking remains low, there may be a problem with the pump compensator displacement control. Replace the pump compensator control assembly and repeat Step 1.
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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
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Unit Injectors
Perform the Injector Solenoid Test on Cat ET in order to determine if all of the injector solenoids are being energized by the ECM. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" for the proper procedure.
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.
- Check for air in the low pressure fuel supply 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. Refer to Testing and Adjusting for more information.
- Replacement of the fuel filters
- Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, "Fuel System - Prime" for the correct procedure.
| 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. |
- Check fuel quality. In temperatures below 0 °C (32 °F), check for solidified fuel (wax). Refer to Special Instruction, SEBD0717, "Diesel Fuels And Your Engine".
- Check the fuel pressure after the fuel filter while the engine is being cranked. Refer to Testing and Adjusting for the correct pressure values. 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. Refer to Testing and Adjusting for more information.
Combustion
Check for combustion problems.