Yanmar 4JH45 Operation Manual page 90

TROUBLESHOOTING
Symptom
Engine is not running smoothly
Operation failure of injection
valve
Uneven fuel injection quantities
Other
Engine stops suddenly
No fuel feed
Other
Abnormal smoke color
Failure of fuel injector
Turbo-charger failure
(If equipped)
Other
Symptom
Insufficient output
84
Probable Cause
Nozzle operation failure
Broken fuel valve spring
Clogged fuel filter
Faulty operation of regulator valve
Air trapped in fuel injection system
Faulty operation of fuel supply pump
Overload operation
Moving parts seized
Slippage of gear box
Fuel level in fuel tank is low
Air trapped in fuel system or fuel
injection
Water trapped in fuel tank
Fuel cock closed
Clogged fuel filter
Broken fuel pipe
Failure of fuel supply pump
Moving parts seized
Controller defects system error
Clogged injection nozzle
Sticking needle valve
Reduction in injection pressure
Poor atomization
Carbon deposit
Clogged air filter
Dirty compressor side
Clogged turbine side
Damaged bearing
Overload operation
Lubricant level too high
Accumulated carbon deposit at
intake/exhaust valve
Dirty air cooler (If equipped)
Improper fuel
Clogged intake/exhaust valve
Probable Cause
Replace
Replace
Replace
Replace
Bleed air from system and prime system
Repair
Reduce load
Disassemble, inspect and conduct servicing
Inspect and repair
Add fuel and prime
Bleed air
Drain water from drain cock and fuel pipe, conduct
priming
Inspect and repair as necessary
Replace
Replace
Replace
Disassemble and repair, or replace
Inspect DTC and conduct servicing
Replace
Replace
Replace
Replace
Clean
Clean
Clean
Clean
Replace
Reduce load
Lower the oil level
Clean
Clean
Replace with proper fuel
Clean
JH Series Operation Manual
Measure
Measure