0122515 JOHNSON "O" RING, Valve guide

Recommended Actions
Fuel Supply
Check the fuel level in the fuel tank. Ensure that adequate fuel is available for the application.Check fuel lines for the following problems: restrictions, collapse and pinched line. Repair the lines and/or replace the lines.
Check the fuel tank for foreign objects which may block the fuel supply. Check for air leaks in the suction line of the fuel pump. Prime the fuel system after you perform the following procedures:
Replacing the fuel filters
Working on the low pressure fuel supply circuit
Replacing fuel injectors
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.
Check the fuel pressure during engine operation. Check the fuel pressure after the fuel filter. Refer to the Systems Operation/Testing and Adjusting manual for the correct pressure values. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling and fuel pressure regulating valve. Derate Mode
Connect Cat ET and check for logged derate events. A derate status flag will appear on Cat ET if an active engine derate is occurring. The engine speed might be limited due to one of the following possible causes: altitude, high exhaust temperatures, air filter restriction, high coolant temperature, aftercooler water temperature and crankcase pressure.Cold Mode Operation and Cold Cylinder Cutout
Use the Caterpillar Electronic Technician (ET) in order to verify that the engine has exited cold mode. During cold mode, fuel injection timing is modified. When the engine is in cold mode, the cold cylinder cutout strategy may be active. Cold mode cylinder cutouts may cause variations in vibration and available power. This is normal operation.Throttle Signal
Use Cat ET in order to monitor the status of the throttle. Observe the throttle position. Verify that the throttle position is smooth from low idle to high idle. The throttle position should reach 100 percent at high idle.Electrical Connector
Check for the correct installation of the ECM connector(s) J1/P1 and/or J2/P2. Check for correct installation of the applicable fuel Injector connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".Injector
Use Cat ET to determine if any active diagnostic codes are present. Check that the injector trim codes have been entered. Use Cat ET to determine if any logged diagnostic codes are present. Perform the "Injector Solenoid Test". Observe that the solenoids for the injectors are being energized on Cat ET. Perform the "Cylinder Cutout Test". Locate the misfiring cylinder. Refer to the diagnostic functional test Troubleshooting, "Injector Solenoids".Fuel Ratio Control Limit (FRC)
Operate the engine under full load. Use Cat ET in order to monitor the following values: turbocharger compressor outlet pressure, fuel position, rated fuel position and Fuel Ratio Control (FRC). The fuel position should equal the rated fuel position. The FRC fuel position should be greater than the rated fuel position.If any of the above values are changing rapidly for no apparent reason, there may be an intermittent problem with the wiring. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".Air Inlet Restriction
Check for an air filter restriction indicator. Replace plugged air filters and/or clean the filters. Repair any leaks.Check the air inlet system for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines.Exhaust Restrictions
Check the exhaust system for the following problems: restrictions, collapse, pinched line and loose fittings. Repair the lines and/or replace the lines.Electronic Control Module (ECM)
If you have replaced the ECM, check the read/change system configuration parameters. Verify that the parameters match the information on the engine information plate. Verify that the correct flash file has been installed.Fuel Position Multiplier (if applicable)
If equipped, use Cat ET to verify that the fuel position multiplier is not affecting the available fuel rack. Refer to Troubleshooting, "Fuel Position Multiplier" if a problem is suspected with the input for the fuel position multiplier.Air Shutoff Valve (if applicable)
Check that both of the air shutoffs are open.