Kubota WG1605-E3, Diagnostic Manual

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ECM SYSTEM
WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM
1-27
Surges/Chuggles
Checks Action
DEFINITION: The engine has a power variation, under a steady throttle or cruise. The vehicle feels as if it speeds up and slows down, with no
change in the accelerator pedal.
Preliminary Checks
• Refer to Important Preliminary Checks.
• Be sure the driver understands the Torque Converter Clutch operation.
Sensor Checks Check the Heated Exhaust Gas Oxygen Sensor (HEGO) performance.
Fuel System Checks
• Check for Rich or Lean symptom that causes the condition. Drive the vehicle at the speed of the
complaint. Monitoring the oxygen sensors will help identify the problem.
• Check the fuel pressure, while the condition exists. Refer to LPG / Natural Gas Fuel System
Diagnosis.
• Verify proper fuel control solenoid operation.
• Verify that the LPG / natural gas manual shut-off valve is fully open.
• Check the in-line fuel filter for restrictions.
Ignition System Checks
• Check for the proper ignition output voltage, using a spark tester.
• Verify that the spark plugs are correct, for use with LPG / natural gas.
• Check the spark plugs. Remove the plugs, and inspect them for the following conditions:
– Wet plugs
– Cracks
– Wear
– Improper gap
– Burned electrodes
– Heavy deposits
• Check the Crankshaft Position (CKP) sensor.
Additional Check
• Check the ECM grounds, for being clean, tight, and in their proper locations.
• Check the generator output voltage.
• Check the vacuum hoses, for kinks or leaks.
• Check Transmission.
KiSC issued 12, 2016 A