20904074 Volvo.Penta Valve guide

Recommended Actions
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.
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.Diagnostic Codes, Event Codes and Derates
Certain diagnostic codes and/or event codes may cause poor performance. Connect Caterpillar Electronic Technician (ET) and check for active codes and/or logged codes. Wait at least 30 seconds in order for any codes to become active. Troubleshoot any codes that are present before continuing with this procedure.Note: Although a sensor's signal may be in the operational range of the sensor, certain failure modes of a sensor may produce an output signal that does not represent an accurate measurement. Use Cat ET to check that the pressures and the temperatures are fluctuating normally. Also check that the values are reasonable for the conditions that are present.Cold Mode Operation
Use Cat ET to verify that the engine has exited cold mode. Cold mode operation may cause a slow throttle response. Some engines use a feature such as the cold cylinder cutout in order to warm the engine during cold mode. Again, ensure that the engine has exited cold mode operation.Electrical Connectors
Check the associated wiring for damage, for abrasion, for corrosion or for incorrect attachment on the following connectors: Electronic Control Module (ECM) connectors and customer connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".Low Pressure Fuel System
Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only. If necessary, add fuel to the fuel tank. If the engine has been run out of fuel, it will be necessary to prime the fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System - Prime".
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.
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 and pinched lines. If problems are found with the fuel lines replace the lines.
Check the fuel tank for debris or foreign objects which may block the fuel supply.
Check the fuel pressure during engine cranking. Check the filtered fuel pressure. Refer to Systems Operation/Testing and Adjusting, "Fuel System Pressure - Test".
Check fuel quality. Refer to Systems Operation/Testing and Adjusting, "Fuel Quality - Test". High Pressure Fuel System
Inspect the high pressure fuel system. Check the following components:
High pressure fuel pump
Fuel rail
Fuel linesDisconnect each harness connector from the pump. Look for fuel on the connectors.If there is fuel in the connectors, clean the connectors. Having clean connectors will help ensure a good connection.Use Cat ET to perform the "Injector Solenoid Test" in order to determine if all of the injector solenoids are being energized by the ECM.Perform the "Cylinder Cutout Test" on Cat ET in order to identify any injectors that might be misfiring.Perform the "Fuel System Functional Test". Cat ET will display an error message that indicates the problem. Follow the repair procedure for the error message:"Fuel Pump Not Timed Correctly" - Remove the high pressure fuel pump and then reinstall the high pressure fuel pump after the timing is set. Then, run the "Fuel System Functional Test" in order to verify that the pump is timed correctly."Fuel Pump Flow Too Low" - Replace the high pressure fuel pump. Then, run the "Fuel System Functional Test" again in order to verify that the problem is resolved."Fuel Rail High Pressure Decay Too High" - Replace the pressure relief valve. Then, run the "Fuel System Functional Test" again in order to verify that the problem is resolved. If the problem is not resolved, refer to Systems Operation/Testing and Adjusting, "High Pressure Fuel Bypass - Test"."Fuel Rail Low Pressure Decay Too High" - Refer to Systems Operation/Testing and Adjusting, "High Pressure Fuel Bypass - Test".Intake Manifold Pressure Sensor
With the engine at full load, monitor "Fuel Position" and "Rated Fuel Limit" on the status screen. If "Fuel Position" does not equal "Rated Fuel Limit", then check intake manifold pressure.
Monitor intake manifold pressure and atmospheric pressure for normal operation on the status screen. Air Inlet and Exhaust System
Check the air inlet and exhaust systems for restrictions and for leaks. Refer to the Operation and Maintenance Manual. Look for an indication of the warning lamp or restriction indicators that are tripped if the filters are equipped with these devices. These indicators are associated with plugged filters. Replace the plugged air filters or clean the plugged air filters per the guidelines of the Operation and Maintenance Manual. Repair any leaks that are found in the system.Valve lash
Refer to the Systems Operation/Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust".