Yanmar 4LHA-HTP Operation Manual page 414

Chapter 3 Fuel Injection Equipment
11. Troubleshooting
Malfunctions
3. The injection
timing is too
retarded and the
engine is
overheating or
the exhaust
contains smoke
4. The nozzle or
the nozzle
holder is not
functioning
properly
The engine
cannot reach its
maximum speed
The engine's
maximum speed
2. The governor flyweights or
is too high
Idling is unstable
2. The governor's idling adjustment
3. The plunger is worn
4. The plunger spring is broken
5. The rubber damper is worn.
6. The governor lever shaft pin is
7. The feed pump blades are not
8. The regulating valve is stuck in
9. The fuel filter element is clogged
10. The nozzle or the nozzle holder
Causes
1. The governor spring is too weak
or is improperly adjusted
2. The control lever is not reaching
the maximum-speed position
3. The nozzle's injection operation is
poor
1. The governor spring is too strong
or is improperly adjusted
governor sleeve movement is not
smooth
1. The injection quantities are not
uniform (the delivery valve is not
operating properly)
is improperly adjusted
worn excessively
operating properly
the open position
and therefore fuel oil delivery is
poor
is not functioning properly
Remedies
Readjust
Inspect, and then repair or replace
Readjust or replace
Readjust
Repair or replace
Readjust or replace
Repair or replace
Inspect or replace
Readjust
Replace the distributor assembly
Replace
Replace
Replace
Repair or replace
Replace
Clean or replace
Inspect and then repair or replace
4LHA Serit