3412E Petroleum Engine Caterpillar

Engine Cranks but Will Not Start

Usage:

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The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.

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 (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 at the fuel tank. Do not rely on the fuel gauge exclusively. 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 must 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.

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, ensure that the Electronic Control Module (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, both of the engine speed/timing connectors and all of 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.

ECM Software

Verify that the correct ECM flash file is installed in the ECM.

Note: If a new ECM or a new personality module chip 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 on the 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 6 MPa (875 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 between 5 and 15 Ohms, replace the injection actuation pressure control valve.

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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.

If the injection actuation pressure during cranking is less than 5000 kPa (725 psi), the high pressure oil supply circuit may have a leak.
1. Unplug the injection actuation pressure control valve and the unit injector connectors.
1. Disable the unit injectors with Cat ET and/or the engine shutdown switch.
1. Remove the valve mechanism covers.
1. Crank the engine while you check the drain holes in the unit injector adapter and the jumper block seals for leaks.
1. Repair any leaks and repeat Step 1.
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.

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 Systems Operation/Testing and Adjusting, "Air in Fuel - Test" for more information.

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NOTICE

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.

Purge air from the low pressure fuel supply circuit. Refer to Systems Operation/Testing and Adjusting, "Fuel System - Prime" for the correct procedure.

Check fuel quality. In temperatures below 0 °C (32 °F), check for solidified fuel (wax). Refer to the applicable Operation and Maintenance Manual topic for details.

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 Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test" for more information.