MAINTENANCE MANUAL OF ENGINE
137
3. Black smoke or grey smoke
Steps
Inspection
position
Fault causes
Troubleshooting
1
Fuel injector
The fuel injector or the injector nozzle
is damaged or blocked, resulting in poor
atomization and insufficient combus-
tion.
Repair or replace (Refer to Sec-
tion 6, Chapter 3 of this Part)
2
Fuel injection
pump
1. The fuel injection is too late, and par-
tial fuel is combusted in the exhaust
process.
2. The fuel supplied by the fuel injec-
tion pump is insufficient, causing une-
venness of the combustion power.
1. Adjust the fuel supply advance
angle to 16°±1° (Refer to Section
4, Chapter 3 of this Part)
2. Calibrate the pump (Refer to
Section 4, Chapter 3 of this Part)
3
Valve
1. The valve is not sealed tightly, re-
sulting in low compression ratio of cyl-
inders.
2. The valve is open slowly, and the
engine is operated roughly.
Grind the valve or adjust the valve
clearance (Refer to Section 1,
Chapter 3 of this Part)
4
Air filter
The air filter is blocked, and the air in-
take quantity is insufficient.
Clean the air filter or change the
filter element.
5
Overload
Overload operation
Reduce the load within specified
range.
4. Insufficient compression pressure of cylinders
Steps
Inspection
position
Fault causes
Troubleshooting
1
Intake and
exhaust
valves
The valves are not sealed tightly.
Grind the valve (Refer to Section
4, Chapter 1, Part II) or adjust the
valve clearance.
2
Valve spring
The valve spring is broken.
Replace (Refer to Section 3,
Chapter 6, Part II)
3
Valve clear-
ance
The valve clearance is inappropriate.
Adjust (Refer to Section 1, Chap-
ter 3 of this Part)
4
Piston ring
Carbon deposit, jamming or serious
wear of the piston ring
Clean the carbon deposit or re-
place it with new one (Refer to
Section 4, Chapter 2, Part II)
5
Cylinder head
Cylinder head
gasket
The cylinder head bolts are loosened or
the cylinder head gasket is damaged.
Tighten the bolts to 135-150N.m
or replace it with a new cylinder
head gasket.
Summary of Contents for KM/4L22
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