Kohler SFGLD480 Operation & Maintenance Manual page 309

SYMPTOM
Engine shows signs of ignition
failures
Knocking
Whenever knocking occurs,
endoscopic examination is
necessary to determine the
extent of the fault and to be
able to change any affected
parts.
If the engine incorporates a
Detonation Detection System,
check the sensors to see if
they fail to detect knocking on
time.
(1)
Engines with NOx sensor or lambda sensor carburetion
(2)
Engines with electronic carburetion
(3)
Engines with Mechanical carburetion
PRODUCT INFORMATION
IO-G-T-00-001e
GAS ENGINES TROUBLESHOOTING
PROBABLE CAUSE
Too lean air-fuel mixture
Spark plug failure
Coil or high-voltage wire failure
Ignition module failure
High temperature of intake air
Oil jet broken or bent
Intake or exhaust valve drop
Excessively advanced ignition
High water temperature in main circuit
1. Not enough coolant
2. Air in the main circuit
3. Water leak
4. Dirty radiator or heat exchanger
5. Fan failed
6. Damaged pump
7. Damaged cylinder head gaskets
Overload due to wrong reading of power
signal
Too rich air-fuel mixture
Broken or damaged spark plug
Overhead valves do not close correctly
Foreign bodies in the combustion chamber
Carburetion control failure
Failure of gas flow regulating valve
Sudden change in gas quality
Seizure
INDEX
B
REMEDY
Readjust carburettor mixture valve.Check
NOx sensor or lambda sensor signal
Check, regap or change spark plus as
appropriate
Change wires or coils that are out of
specifications
Change module
Clean air cooler, check thermostats and
auxiliary circuit pump
Change jet. Inspect piston dome for signs of
overheating and, if any, change piston
Change cylinder head and, where
appropriate, sleeve, piston...
Check ignition timing
1. Add coolant into the circuit
2. Vent the circuit
3. Repair leak
4. Clean radiator or heat exchanger
5. Change fan
6. Repair or change pump
7. Change cylinder head gasket
Calibrate power signal
Readjust carburettor mixture valve.
Check MAP and MAT sensors signal
Check NOx sensor or lambda sensor signal
Change spark plug
Change or rework cylinder head
Remove foreign bodies
Check control program
Change gas flow regulating valve
Check against chromatogram if available.
Readjust carburettor mixture valve
Check programming if electronic system
installed
Change any parts concerned.
6.1.6
DATE
February 2016
O&M_2.002211.810_A_10_2016
(3)
(2)
Dep. 2
(1)
(2)
(1)
6/10