Yanmar 4LHA-HTP Operation Manual page 413

Chapter 3 Fuel Injection Equipment
Jl. Troubleshooting
Malfunctions
The engine
exhaust contains
smoke and the
engine "knocks"
The engine
output is unstable
2. The amount of fuel or pressure
3. The injection pump is sucking air
4. The regulating valve is stuck in
5. The plunger is sticking and does
6. The plunger spring is broken
7. The control sleeve is not sliding
8. The governor lever is not
9. The delivery valve spring is
10. The delivery valve is not sliding
11. The nozzle or the nozzle holder
12. The injection timing is incorrect
Insufficient
output
1. The specified full-load injection
1. The injection
quantity is
insufficient 2. The control lever is not reaching
3. The governor spring is weak and
4. The plunger is worn
5. The delivery valve seating
2. The injection
timing is too
advanced and
the engine is
"knocking"
Causes
1. The injection timing is incorrect
2. The nozzle or nozzle holder is
functioning incorrectly
3. The injection quantity is
excessive
1. The fuel filter element is clogged
and fuel oil delivery is poor
delivered by the feed pump is too
little
the open position
not travel its full stroke
smoothly
operating properly or is worn
excessively
broken
properly
is not functioning properly
quantity is not delivered
the maximum speed position
therefore the governed speed is
too low
portions are damaged
3-1-56
Remedies
Readjust the timing
Inspect, then repair or replace
Readjust
Clean or replace
Inspect and repair
Inspect and repair
Replace
Replace the distributor assembly
Replace
Repair or replace
Repair or replace
Replace
Repair or replace
Inspect, and then repair or replace
Readjust
Readjust
Readjust
Replace
Replace the distributor assembly
Replace
Readjust
i 4LHA Series i