Kubota WG1605-E3, Diagnostic Manual

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ECM SYSTEM
WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM
1-25
Poor Fuel Economy
Checks Action
DEFINITION: Fuel economy, as measured by refueling records, is noticeably lower than expected. Also, the economy is noticeably lower, than
it was on this vehicle at one time, as previously shown by refueling records.
Preliminary Checks
• Refer to Important Preliminary Checks.
• Check the air cleaner element (filter), for dirt or being plugged.
• Visually (Physically) check the vacuum hoses, for splits, kinks, and proper connections.
• Check the operators driving habits, for the following items:
– Is there excessive idling, or stop and go driving?
– Are the tires at the correct air pressure?
– Are excessively heavy loads being carried?
– Is their often rapid acceleration?
• Suggest to the owner, to fill the fuel tank, and to recheck the fuel economy.
• Suggest that a different operator, use the equipment and record the results.
Fuel System Checks
• Check the DSR fuel pressure. Refer to LPG / Natural Gas Fuel System Diagnosis.
• Check the fuel system for leakage.
Sensor Checks • Check the Temperature Manifold Absolute Pressure (TMAP) sensor.
Ignition System Checks
• 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
Cooling System Checks • Check the engine thermostat, for always being open, or for the wrong heat range.
Engine Mechanical Check
• Check the engine for the following:
– Engine compression
– Valve timing
• Improper or worn camshaft. Refer to Engine Mechanical, in the Service Manual.
Additional Check
• Check the transmission shift pattern. Refer to the OEM Transmission Controls section of the
Service Manual.
• Check for dragging brakes.
KiSC issued 12, 2016 A