56654 Mercury KEY, IMPELLER DRIVE

Probable Causes
Diagnostic codes
Event codes
Derates
Parameters of the Electronic Control Module (ECM)
Throttle signal
Air inlet and exhaust system
Fuel supply
Cylinder performance
Electrical connectors
Electronic unit injectorsRecommended Actions
Diagnostic Codes, Event Codes and Derates
Certain diagnostic codes, event codes and/or derates may cause poor performance. Connect Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any active codes before continuing with this procedure.Note: If a E390 Fuel Filter Restriction is logged and/or active, replace the fuel filters.Note: If a E198 Low Fuel Pressure is logged and/or active, refer to the symptom Troubleshooting, "Fuel Pressure Is Low". ECM Parameters
Verify that the correct parameters are being used.
Use Cat ET to verify the following parameters at maximum speed: the boost pressure, the smoke limit, the torque limit and the amount of fuel that is delivered.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. Refer to the appropriate diagnostic test for your application:
Troubleshooting, "Speed Control (PWM) - Test"
Troubleshooting, "Speed Control (Switch) - Test"
Troubleshooting, "Speed Control - Test"Air Inlet and Exhaust System
Check the air filter restriction indicator, if equipped. Clean plugged air filters or replace plugged air filters. Refer to the Operation and Maintenance Manual.
Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Systems Operation/Testing and Adjusting.Fuel Supply
Visually check the fuel level. Do not rely on the fuel gauge only. If necessary, add fuel. If the engine has been run out of fuel, it will be necessary to purge the air from the fuel system. Refer to Operation and Maintenance Manual.
Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.
Do not loosen any high pressure fuel lines when the engine is running. The high pressure in the fuel lines can cause personal injury or death. Wait 60 seconds after the engine has stopped to allow pressure to purge before any service or repair is performed on the engine fuel lines.
Check the fuel lines for the following problems: restrictions, collapsed lines, pinched lines and loose connections. If problems are found with the low pressure fuel lines, repair the lines and/or replace the lines. If the high pressure fuel lines have a leak, the high pressure fuel lines must be replaced. Refer to the Disassembly and Assembly manual.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Prime the fuel system if any of the following procedures have been performed:
Replacement of the fuel filters
Service on the low pressure fuel supply circuit
Replacement of unit injectorsNote: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel. Refer to Testing and Adjusting.
Check the fuel tank for foreign objects which may block the fuel supply.
Check the fuel filters.
Check the diesel fuel for contamination. Refer to Testing and Adjusting.
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.Cylinder Performance
Check for correct installation of the unit injector connectors. Check for correct installation of all other applicable connectors. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Perform the "Cylinder Cutout Test" on Cat ET in order to identify any injectors that might be misfiring.
If Cat ET indicates a problem, remove the electronic unit injector from the suspect cylinder. Refer to Disassembly and Assembly.Note: Discard all fuel injection lines after use. Fuel injection lines must only be used one time.
Perform a compression test. Refer to Testing and Adjusting. Possible causes of low compression are shown in the following list:
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 problem.
Reinstall the electronic unit injectors that were removed.Note: Discard all fuel injection lines after use. Fuel injection lines must only be used one time.Electronic Unit Injectors
Perform the "Injector Solenoid Test" on Cat ET in order to determine if all of the injector solenoids are being energized.
Perform the "Cylinder Cutout Test" on Cat ET in order to identify any injectors that might be misfiring.
If Cat ET indicates a problem, remove the electronic unit injector from the suspect cylinder and install a new electronic unit injector. Refer to Disassembly and Assembly.Note: Discard all fuel injection lines after use. Fuel injection lines must only be used one time.
Ensure that the repairs have eliminated the problem. If there is still a problem, refer to the circuit test Troubleshooting, "Injector Solenoid - Test".