826709110 Mercury NUT, (.312-18)

Probable Causes
Diagnostic codes and event codes
Starting aids
Coolant temperature sensor
Low-pressure fuel system
Cooling system
Flash fileRecommended Actions
Diagnostic Codes and Event Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector. Check for active diagnostic codes and event codes.Look for diagnostic codes that are active or logged. Check for codes that are related to the high-pressure fuel system, the low-pressure fuel system, and the engine speed/timing circuit. Use the appropriate circuit test to troubleshoot any active codes before continuing.Also, look for event codes that are active or logged. check for codes that are related to the low-pressure fuel system. If there is evidence of a problem with the fuel system, repair the low-pressure fuel system before continuing.Note: Diagnostic codes that are logged repeatedly could be a sign of intermittent electrical problem. Event codes that are logged repeatedly may be evidence of an impending problem with the engine.Starting Aids
Ensure that the ether canister is not empty or low. Replace the ether canister if the ether canister is empty or low. Refer to Troubleshooting, "Ether Starting Aid - Test". Note: Cold mode helps reduce the possibility of engine damage and helps to minimize white smoke. An engine running in cold mode may also sound different and appear to run rougher.
Use Cat ET to verify that the engine has exited cold mode. During cold mode operation, fuel injection is driven into a multi-shot strategy. Cold mode engine operation is evident by a reduction in rail pressure and an adjustment in injection timing. For cold mode to be activated, engine coolant temperature must be below 69° C (156° F). Also, the engine load factor must be below 30 percent for standby gensets, or 40 to 45 percent load factor for prime or continuous ratings. Cold mode remains active until the engine coolant temperature warms to 71.° C (160° F), or the stated load factor increases above the threshold.
Check for proper operation of the jacket water heater. If necessary, repair the jacket water heater or replace the jacket water heater. Coolant Temperature Sensor
Use Cat ET to verify that the engine has exited cold mode.
Compare the coolant temperature from Cat ET to the coolant temperature that is obtained from the 6V-9130 Temperature Adapter (MULTIMETER). Ensure that the temperature readings are reasonable for the conditions that are present.
If a problem is suspected with the sensor, refer to Troubleshooting, "Sensor Signal (Analog, Passive) - Test" for details that are related to troubleshooting the sensor and the sensor circuit. Low Pressure Fuel System
Perform a visual inspection of the fuel system components.
Check the fuel pressure during engine cranking. Check the filtered fuel pressure. Refer to Systems Operation/Testing and Adjusting for the correct pressure values.
If the fuel pressure is OK, check for air in the fuel system. Refer to Systems Operation/Testing and Adjusting for details.
If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, refer to Troubleshooting, "Fuel Pressure is Low" for more information that is related to troubleshooting the low-pressure fuel system. Cooling System
Check for an internal coolant leak into a cylinder and/or the exhaust. Refer to Systems Operation/Testing and Adjusting for information on inspecting the cooling system.Flash File
Verify that the latest flash file is installed. Refer to Troubleshooting, "ECM Software - Install".