C280 Marine and Petroleum Engines Caterpillar

Fuel Consumption Is Excessive

Usage:

Probable Causes

Active codes and logged codes
Excessive idle or high load
Fuel quality
Fuel system
Engine speed/timing
Fuel injection system
Air inlet and exhaust
Check for damaged accessory equipment

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.

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Table 1
Troubleshooting Test Steps	Values	Results
1. Active Codes and Logged Codes A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM). B. Monitor the diagnostic codes on Cat ET. Check for active diagnostic codes. Specifically check for codes related to the fuel system, air inlet and exhaust , and speed timing. Note: Wait at least 30 seconds in order for diagnostic codes to become active.	Codes	Result: There are logged or active diagnostic codes. Repair: Troubleshoot any codes before continuing with this procedure. Verify that the repair eliminated the problem. Result: There are no logged or active diagnostic codes. Proceed to Test Step 2.
2. Excessive Idle or High Load A. Use Cat ET to check the Current Totals for excessive idle time and/or for a high load factor. These factors would be indicative of poor operating habits.	Idle time or load	Result: The idle times or load was excessive. Reduce idle times or load. Verify that the repair eliminated the problem. Result: The idle times or load was not excessive. Proceed to Test Step 3.
3. Fuel Quality A. The grade of the fuel affects the rate of fuel consumption. Refer to the engines Operation and Maintenance Manual for additional information. Cold weather adversely affects the characteristics of the fuel. Monitor the status screen on Cat ET in order to verify that the engine has exited cold mode (if applicable). Refer to the Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation.	Fuel quality	Result: The fuel quality meets specifications. Proceed to Test Step 4. Result The fuel quality does not meet specifications. Repair: Replace the fuel with fuel that meets specifications. Verify that the repair eliminated the problem.
4. Fuel System A. Inspect the fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for additional information. B. Check for the proper operation of the fuel transfer pump.	Fuel system	Result: The fuel system is OK. Proceed to Test Step 5. Result The fuel system is not OK. Repair: Make the necessary repairs. Verify that the repair eliminated the problem.
5. Calibration Procedure of the Engine Speed/Timing A. Perform a speed/timing sensor calibration. Refer to the calibration procedure Troubleshooting, "Timing - Calibrate".	Calibration	Result The speed timing calibration was performed. Proceed to Test Step 6.
6. Unstable Injection Actuation System A. Check for correct installation of the J1/P1 and J2/P2 Electronic Control Module (ECM) connectors and the injector connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect". B. Perform the "Injector Solenoid Test" on Cat ET in order to determine if all of the injector solenoids are being energized by the ECM. C. Perform the "Cylinder Cutout Test" on Cat ET in order to identify any injectors that might be misfiring. Refer to Troubleshooting, "Injector Solenoid - Test".	Injection actuation	Result The tests completed successfully. Proceed to Test Step 7. Result The tests did not complete successfully. Repair: Make the necessary repairs. Verify that the repair eliminated the problem.
7. Restriction in the Air Inlet and Exhaust A. Inspect the air filter for a restriction. B. Check the air inlet and exhaust system for restrictions and/or for leaks.	Restrictions	Result There are restrictions in the air inlet or exhaust system. Repair: Remove or repair the restrictions. Verify that the repair eliminated the problem. Result There are no restrictions in the air inlet or exhaust system. Proceed to Test Step 8.
8. Check for Damaged Accessory Equipment A. Check all accessory equipment for problems that may create excessive load on the engine.	Accessory equipment	Result There is damaged accessory equipment. Repair: Remove or repair the accessory equipment. Verify that the repair eliminated the problem.

If 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).