PIN AS 1979728 - Caterpillar

Probable Causes
Unit injectors
Fuel supply
Air supply
Engine idle
Accessory equipmentRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Unit Injectors
A. Check for correct installation of the J1/P1 and J2/P2 connectors for the Electronic Control Module (ECM).
B. Check for correct installation of the J300/P300 connectors for the unit injectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Unit Injectors
Result: The J1/P1 and J2/P2 connectors have been installed correctly.
Result: The J300/P300 connectors have been installed correctly.
Proceed to Test Step 2.
Result: The connectors have not been installed properly.
Repair the connectors.
2. Fuel Supply
A. Check the fuel pressure. Refer to Systems Operation/Testing and Adjusting.
B. Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines.
C. Check the fuel tank for foreign objects which may block the fuel supply.
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.
D. Cold weather adversely affects the characteristics of the fuel. Refer to the Operation and Maintenance Manual.
E. Check the fuel pressure after the fuel filter while the engine is being cranked. For the correct pressure values, refer to the Systems Operation/Testing and Adjusting manual.
Fuel Supply
Result: The fuel lines are OK.
Result: The fuel lines are NOT OK.
Replace or repair the fuel lines.
Result: The fuel tank does not have a blockage of the fuel supply.
Result: The fuel tank has a blockage of the fuel tank.
Repair the blockage in the fuel tank.
Result: The fuel pressure is OK.
Proceed to Test Step 3.
Result: The fuel pressure is NOT OK.
Make the necessary repairs.
3. Air Supply
A. Check for restrictions in the air inlet system. Refer to Systems Operation/Testing and Adjusting.
Air inlet system
Result: The are no restrictions in the air inlet system.
Proceed to Test Step 4.
Result: There are restrictions in the air inlet system.
Repair the restrictions in the air inlet system.
4. Engine Idle
A. Check the parameter for the low engine idle (if applicable). Refer to Troubleshooting, "System Configuration Parameters".
Parameters
Result: The low engine idle parameters are OK.
Proceed to Test Step 5.
Result: The low engine idle parameters are NOT OK.
Repair the low engine idle parameters.
5. Engine Accessories
A. Inspect any engine accessories and the transmission (if applicable).
Engine accessories
Result: An engine accessory is creating an excessive load.
Repair the engine accessory.
Complete the procedure in the order in which the steps are listed.The procedure corrected the issue. Return the engine to service.The procedure did not correct the issue.Contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).