0340914 JOHNSON SPRING, Spark control

Probable Causes
Diagnostic codes
ECM parameters
Throttle position sensor
Air intake and exhaust system
Fuel supply
Individual malfunctioning cylinders
Fuel injection nozzlesRecommended Actions
Diagnostic Codes
Check for active diagnostic codes on the electronic service tool. Troubleshoot any active codes before continuing with this procedure.ECM Parameters
Ensure that the fault is not a programmed parameter.
Ensure that the correct mode was selected by using the electronic service tool.
Use the electronic service tool to verify the correct engine rating for the engine.
Use the electronic service tool to verify the maximum engine speed limit.
Use the electronic service tool to reset the parameters to the OEM specifications.
Ensure that the repairs have eliminated the faults.
If the repairs have not eliminated the faults proceed to "Throttle Position Sensor". Throttle Position Sensor
Use the electronic service tool and observe the signal for the throttle position sensor.
If the signal is erratic, refer to Troubleshooting, "Throttle Position Sensor Circuit - Test".
If the engine has a throttle switch refer to Troubleshooting, "Throttle Switch Circuit - Test".
If the repairs have not eliminated the faults proceed to "Air Intake and Exhaust System". Air Intake and Exhaust System
Check the air filter restriction indicator, if equipped.
Ensure that the air filter is clean and serviceable.
Check the air intake and the exhaust system for the following defects:
Blockages
Restrictions
Damage to the air intake and exhaust lines and hoses
Make all necessary repairs to the engine.
Ensure that the repairs have eliminated the diagnostic code.
If the fault has not been eliminated, proceed to "Fuel Supply". Fuel Supply
Check the fuel pressure. Refer to Systems Operation, Testing and Adjusting, "Fuel System Pressure - Test".
Ensure that the fuel system has been primed. Refer to Systems Operation, Testing and Adjusting, "Fuel System - Prime".
Check the diesel fuel for contamination. Refer to Systems Operation, Testing and Adjusting, "Fuel Quality - Test".
Check for air in the fuel system. Refer to Systems Operation, Testing and Adjusting, "Air in Fuel - Test".
Check that the fuel lines are tight and secured properly.
Check for fuel supply lines that are restricted.
Check the fuel filters.
Visually check the fuel tank for fuel. The fuel gauge may be faulty.
If the engine has a water separator, check for water in the fuel.
Ensure that the fuel supply valve is in the full OPEN position.
If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
If the repairs do not eliminate the fault proceed to "Individual Malfunctioning Cylinders". Individual Malfunctioning Cylinders
With the engine speed at a fast idle, loosen the high pressure fuel line to the fuel injection nozzle of number 1 cylinder. Note if there is any reduction in engine speed. Tighten the high pressure fuel line to the fuel injection nozzle.
If all cylinders have been checked and no faults were detected proceed to "Fuel Injection Nozzles". Fuel Injection Nozzles
Remove the fuel injection nozzles from the cylinder head. Refer to Disassembly and Assembly, "Fuel Injection Nozzles - Remove".
Check the fuel injection nozzles. Refer to Testing and Adjusting, "Fuel Injection Nozzle - Test".
Install the fuel injection nozzles in the cylinder head. Refer to Disassembly and Assembly, "Fuel Injection Nozzles - Install".
Ensure that the repairs have eliminated the fault.