Fuel Consumption Is Excessive
- Look for excessive idle or high load
- Logged diagnostic codes or active diagnostic codes
- Fuel quality
- Unstable fuel supply
- Calibration procedure of the engine speed/timing
- Unstable injection system
- Restriction in the air inlet and exhaust
- Check for damaged accessory equipment
Note: The procedures have been listed in order of probability. Complete the procedures in order.
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| Troubleshooting Test Steps | Values | Results |
|---|---|---|
1. Excessive Idle or High Load A. Use Cat® Electronic Technician (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. Repair: Reduce idle times or load. Result: The idle times or load was not excessive. Proceed to Test Step 2. |
2. Diagnostic Codes A. Check for logged diagnostic codes or active diagnostic codes. If a diagnostic code is logged or active refer to Troubleshooting, "Diagnostic Trouble Codes" for more information. |
Codes |
Result: There are logged or active diagnostic codes. Repair: Troubleshoot any logged or active diagnostic codes before continuing with this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes" for more information. Result: There are no logged or active diagnostic codes. 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. 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. |
4. 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 to determine if all the injector solenoids are being energized by the ECM. C. Perform the "Cylinder Cutout Test" on Cat ET 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 5. Result The tests did not complete successfully. Repair: Make the necessary repairs. Verify that the repair resolved the problem. |
5. 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. Result There are no restrictions in the air inlet or exhaust system. Proceed to Test Step 6. |
6. 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. |
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