LOCATOR AS-SEAL 6V4003 - Caterpillar

Note: If the symptom is intermittent and the symptom cannot be repeated, refer to Troubleshooting, "Intermittent Low Power or Power Cutout is Intermittent". If the symptom is consistent and the symptom can be repeated, continue with this procedure.Probable Causes
Engine derate or active codes
Cold mode
Electrical connectors
Low compression (cylinder pressure)
Individual malfunctioning cylinder
Valve lash
Faulty fuel injector nozzle
Throttle signal
Fuel supply
Air inlet and exhaust systemEngine Derate or Active Codes
Some engine monitoring parameters that are capable of triggering an engine derate do not produce an event code. Connect Caterpillar Electronic Technician (ET) in order to check for a derate of the engine.Certain diagnostic codes and may cause poor performance. Use Cat ET to check for active codes and for logged codes. Troubleshoot any codes that are present before you continue with this procedure.Note: Although a sensor's signal may be in the operational range of the sensor, the signal may not represent the actual reading. Use Cat ET to check that the pressures and the temperatures are fluctuating. Also check that the values are reasonable for the conditions that are present.Cold Mode
The Electronic Control Module (ECM) limits engine power during cold mode operation. The ECM may cut out certain engine cylinders. This will increase startability and this will reduce warm up time. Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. Cold mode remains active until the engine has warmed or a time limit is exceeded.Electrical Connectors
Check for correct installation of the J14/P14 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".Low Compression (Cylinder Pressure)
Perform a compression test. Refer to Systems Operation, Testing and Adjusting, "Compression - Test ".
If low compression is noted on any cylinders, investigate the cause and rectify the cause.Possible causes of low compression are shown in the following list:
Loose glow plugs (if equipped)
Faulty piston
Faulty piston rings
Worn cylinder bores
Worn valves
Faulty cylinder head gasket
Damaged cylinder head
Perform all necessary repairs.
Ensure that the repairs have eliminated the faults.Individual Malfunctioning Cylinders
With the engine speed at a fast idle, loosen the high pressure fuel line to the fuel injector of number one cylinder. Note if there is any reduction in engine speed. Tighten the high pressure fuel line to the fuel injector.
Individually repeat this procedure for each fuel injector. If there is no reduction in the engine speed, investigate the cause of the malfunction.Valve Lash
Check valve lash on misfiring cylinder. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure.Faulty Fuel Injector Nozzle
Remove the suspect fuel injection nozzle. Test the nozzle by using the 5P-4150 Nozzle Testing Group. Refer to Systems Operation, Testing and Adjusting, "Fuel System" for the proper testing procedure. Replace the fuel injector nozzles, as needed.Throttle Signal
Monitor the status for "Throttle Position" on Cat ET. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed. If a problem is suspected with the throttle, refer to the appropriate troubleshooting procedure for troubleshooting the throttle signal.Fuel Supply
Visually check the fuel level in the fuel tank. Do not