0383437 JOHNSON FLOAT ASSEMBLY

Recommended Actions
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine idle, full load, or a specific operating temperature. Troubleshooting the symptoms under other conditions may give misleading results.Diagnostic Codes, Event Codes and Derates
Certain diagnostic codes and/or event codes may cause poor performance. Connect the Caterpillar Electronic Technician (ET) and check for active codes and/or logged codes. 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.Flash File
Verify that the latest flash file has been installed into the ECM.Parameters
Verify that the correct parameters are being used.Electrical Connectors
Disconnect the J1/P1 and J2/P2 ECM connectors. Inspect each connector for moisture and corrosion. Also, inspect the harness and connectors for the unit injectors from the ECM to the valve cover. Refer to Troubleshooting, "Electrical Connectors - Inspect".Unit Injectors
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 check the performance of each cylinder. Refer to Troubleshooting, "Injector Solenoids - Test". Intake Manifold Pressure Sensor
Monitor the status of "Fuel Position", "Rated Fuel Limit", and "FRC Fuel Limit" on Cat ET while the engine is operating under full load. These parameters should agree with the following:
Table 1
"Fuel Position" = "Rated Fuel Limit"
and
"Fuel Position" < "FRC Fuel Limit" If "Fuel Position" equals "Rated Fuel Limit" and "Fuel Position" is less than "FRC Fuel Limit", the electronics are operating correctly.
Monitor the status of "Intake Manifold Air Pressure" and "Atmospheric Pressure" for normal operation on Cat ET. When the engine is not running, "Intake Manifold Air Pressure" should be 0 kPa (0 psi). Air Inlet and Exhaust System
Check the air filter restriction indicator for a plugged filter. If necessary, service the engine. Refer to the Operation and Maintenance Manual.
Check the air inlet and exhaust system for restrictions and/or leaks. Refer to Testing and Adjusting. Fuel Supply
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 the Systems Operation/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.
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 conditions: 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.
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
Replacement of fuel rail
Replacement of fuel transfer pump
Replacement of high fuel pressure pump
Replacement of fuel lines
Positive testing for air in the fuel systemRefer to Systems Operation/Testing and Adjusting, "Fuel System". If necessary, check the entire fuel system.
Check fuel quality. Refer to Systems Operation/Testing and Adjusting, "Fuel System".