Yanmar 4JH45 Operation Manual page 91

12/05
Symptom
Insufficient fuel injection
Insufficient injection by fuel
injection nozzle
Compressed gas leak in the
engine cylinder
Turbo-charger failure
(If equipped)
Other
Knocking
Failure of fuel injector
Other
JH Series Operation Manual
Probable Cause
Oil leak from fuel injection pipe joint
Clogged fuel filter
Clogged fuel pipe
Failure of fuel supply pump
Clogged injection hole
Faulty valve seat
Sticking nozzle
Loose fuel injection pipe joint
Worn nozzle
Gas leak from intake/exhaust valve
Worn upper portion of cylinder bore
Worn piston ring
Sticking piston ring
Clogged air filter
Dirty compressor side
Clogged turbine nozzle
Damaged bearing
Improper fuel
Clogged exhaust duct
Seized or overheated moving parts
Insufficient seawater
Insufficient feed of engine oil
Controller defects system error
Broken fuel valve spring
Sticking nozzle
Poor atomization
Insufficient seawater
Piston clearance excessive
Bearing clearance excessive
Improper fuel
Water trapped in fuel
Poor compression
TROUBLESHOOTING
Measure
Tighten
Replace
Clean
Repair
Replace
Replace
Replace
Tighten
Replace
Conduct fitting of the valve
Lap or replace
Replace
Overhaul or replace
Clean
Clean
Clean
Replace
Replace with correct fuel
Clean
Disassemble and conduct servicing
Inspect seawater pump
Disassemble and clean engine oil pump and filter
Inspect DTC and conduct servicing
Replace
Replace
Replace
Replace seawater pump impeller
Replace
Replace
Replace with correct fuel
Replace fuel
Inspect and service
85