3512B Oil Well Servicing Engine (ADEM III) Caterpillar

Probable Causes

• Engine shutdown switch (if applicable)

• Engine start switch

• Engine speed/timing sensor(s)

• Electrical connections

• Fuel supply

Recommended Actions

Engine Shutdown Switch (if applicable)

Use Caterpillar Electronic Technician (ET) to monitor the status of the engine. Check for active shutdowns due to the engine shutdown switch. Determine the cause for the active shutdown and make any repairs necessary.

Engine Start Switch

Check the engine start switch on Cat ET. Look for an intermittent problem in the wiring for the engine start switch.

Engine Speed/Timing Sensor(s)

Check Cat ET for a 190-08 diagnostic code that has been logged for the primary engine speed/timing sensor. If the engine is equipped with a secondary engine speed/timing sensor, check for a 342-08 diagnostic code that has been logged for the secondary engine speed/timing sensor. Refer to the diagnostic functional test Troubleshooting, "Engine Speed/Timing Sensor".

Electrical Connectors

1. Check Cat ET for the following logged diagnostic codes: 168-01 and 168-02. Follow the battery wires from the ECM back to the battery compartment. Refer to the electrical system schematic. Inspect the wires and the power relay. Check the power to the ECM and to the ground connections. Refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply".

2. Check for correct installation of the J1/P1 and J2/P2 Electronic Control Module (ECM) connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors".

3. Inspect the battery wires from the ECM back to the battery compartment. Refer to the Electrical System Schematic. Inspect the wires and the power relay. Check the power and ground connections to the ECM. Refer to Troubleshooting, "Electrical Power Supply" for more information.

Fuel Supply

1. 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.

2. Check the fuel tank for foreign objects which may block the fuel supply.

3. 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

   Refer to the Operation and Maintenance Manual for the correct procedure.

   Note: A sight glass in the fuel supply line is helpful in diagnosing air in the fuel.

4. Cold weather adversely affects the characteristics of the fuel. Refer to Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold weather operation.

5. Check the fuel pressure during engine cranking. Check the fuel pressure after the fuel filter. Refer to the Systems Operation/Testing and Adjusting manual 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.