COMPRESSOR AS 0R3403 - Caterpillar

Use this procedure to troubleshoot excessive fuel consumption.Probable Causes
Excessive idling or high load
Fuel quality
Speed/timing
Fuel injectors
Inlet air restriction
Exhaust restriction
Driven equipmentRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check for Excessive Idling or High Load
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Use Cat ET to check the following "Current Totals":
- Excessive idle time
- High load factor
Note: These factors would be indicative of poor operating habits.
Idle Time or High Load
Result: The idle time and high load are not excessive.
Proceed to Test Step 2.
Result: The idle time and/or high load was excessive.
Repair: Reduce idle time or high load.
If the problem is not resolved, proceed to Test Step 2.
2. Check the Fuel Quality
A. Obtain a fuel analysis. The grade of the fuel affects the rate of fuel consumption. Refer to the engines Operation and Maintenance Manual for additional information.
B. Ensure that the fuel quality is not being affected by cold-weather conditions.
Fuel Quality
Result: The fuel quality is OK.
Proceed to Test Step 3.
Result: The fuel quality is NOT OK.
Repair: Replace the fuel.
If the problem is not resolved, proceed to Test Step 3.
3. Perform a Speed/Timing Calibration
A. Refer to Troubleshooting, "Timing - Calibrate" for additional information.
Calibration
Result: The speed timing calibration was performed.
Proceed to Test Step 4.
4. Test the Fuel Injectors
A. Connect Cat ET.
B. Use Cat ET to perform the following fuel injector tests:
- "Injector Solenoid Test"
- "Cylinder Cutout Test"
Refer to Troubleshooting, "Cat ET Service Features" for additional information.
Fuel Injectors
Result: The tests were successful.
Proceed to Test Step 5.
Result: The tests were not successful.
Repair: Diagnose the problem. Repair or replace damaged components.
If the problem is not resolved, proceed to Test Step 5.
5. Check for a Restriction in the Inlet Air System
A. Check the air filter restriction indicator, if equipped. Refer to the Operation and Maintenance Manual for additional information.
B. Measure the inlet air restriction for each turbocharger. Refer to Troubleshooting, "Inlet Air Is Restricted" for additional information.
Restriction
Result: The inlet air restriction is OK.
Proceed to Test Step 6.
Result: The inlet air restriction is NOT OK. An imbalance in the system is discovered.
Repair: Repair or replace damaged inlet air system components. Equalize the inlet air restriction for each of the turbochargers.
If the problem is not resolved, proceed to Test Step 6.
6. Check for a Restriction in the Exhaust System
Note: A restriction of the exhaust can cause high cylinder temperatures.
A. Measure the exhaust restriction during engine operation with a load. For data that is specific to your engine, refer to the Technical Marketing Information (TMI).
Restriction
Result: The exhaust restriction measurement is OK.
Proceed to Test Step 7.
Result: The exhaust restriction measurement is NOT OK.
Repair: Repair or replace damaged exhaust system components.
If the problem is not resolved, proceed to Test Step 7.
7. Inspect the Driven Equipment
Driven Equipment
Result: The driven equipment is NOT OK.
Repair: Repair or replace damaged driven 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).