CYLINDER GP-COUPLER 4555975 - Caterpillar

Probable Causes
Air inlet or exhaust system
Engine speed/timing sensor
Atmospheric pressure sensor
Boost pressure sensor
"Fuel Position" and/or "FRC Fuel Limit"
Flash file
Fuel quality
Valve adjustmentRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Air Inlet and Exhaust System
A. Check the air inlet system, air filter, air inlet piping, and exhaust system for restrictions and/or leaks.
B. Ensure that the turbocharger is in working order.
C. Repair any leaks that were found. Remove any restrictions that were found and replace any damaged components that were found.
Restrictions
Result: There are no restrictions or leaks in the air inlet or exhaust system.
Proceed to Test Step 2.
Result: There are restrictions and leaks in the air inlet or exhaust system.
Repair: Make the necessary repairs, and refer to Systems Operation, Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure.
2. Engine Speed/Timing
A. Check the calibration of the engine speed/timing sensor. Refer to Troubleshooting, "Engine Speed/Timing Sensor - Calibrate".
B. Verify that the crankshaft and the camshaft drive gears are set with the proper orientation. Refer to the Disassembly and Assembly manual.
Timing Signal
Result: The timing sensor is operating properly and the crankshaft and camshaft drive gears are aligned.
Proceed to Test Step 3.
Result: The timing sensor is not operating properly and the crankshaft and camshaft drive gears are not aligned.
Repair: Repair the timing sensor and properly align the crankshaft and camshaft drive gears. Refer to Troubleshooting, "Engine Speed/Timing Sensor - Calibrate" for troubleshooting information.
Verify that the repair eliminated the problem.
3. Atmospheric Pressure Sensor
A. Remove the atmospheric pressure sensor and inspect the sensor.
B. Check the Caterpillar Electronic Technician (ET) for active diagnostic codes on the sensor. If no active diagnostic code exists, the sensor may be used. The correct reading for the atmospheric pressure is between 50 kPa (7.25 psi) and 100 kPa (14.5 psi).
Pressure Sensor
Result: The atmospheric pressure sensor is properly working and shows no signs of debris, moisture, and ice.
Proceed to Test Step 4.
Result: The atmospheric pressure sensor is not properly work and has either debris, moisture, and/or ice on the sensor.
Repair: Remove the debris, moisture, or ice from the sensor and reuse. If sensor is not working properly replace the sensor.
4. Boost Pressure Sensor, "Fuel Position", and/or "FRC Fuel Limit"
A. Monitor the status of "Fuel Position" and "Rated Fuel Limit" while the engine is operating under full load. If "Fuel Position" equals "Rated Fuel Limit", and "Fuel Position" is less than "FRC Fuel Limit" the Electronic Control Module (ECM) is providing the correct control.
B. Monitor the status of "Boost Pressure" and "Atmospheric Pressure" on Cat ET and verify that there are no active codes for the boost pressure sensor. When the engine is not running, "Boost Pressure" should be 0 kPa (0 psi).
Note: A problem with the "FRC Fuel Limit" will only cause black smoke during acceleration. A problem with the "FRC Fuel Limit" will not cause black smoke during steady state operation.
Pressure Sensor
Result: The boost pressure sensor, "Fuel Position" and "FRC Fuel Limit" are OK.
Proceed to Test Step 5.
Result: The boost pressure sensor, "Fuel Position" and "FRC Fuel Limit" are not correct