MAINTENANCE MANUAL OF ENGINE
141
9. Low power
Steps
Inspection
position
Fault causes
Troubleshooting
1
Diesel filter or
fuel pump
The fuel inlet/outlet pipe or strainer
is blocked.
Clean or replace
2
Fuel injector
The fuel injector is damaged or
blocked, the fuel injector pressure is
inappropriate or the atomization is
poor.
Repair or replace (Refer to Section 6,
Chapter 3 of this Part)
3
Fuel injection
pump
The fuel injection pump does not
operate smoothly.
1. The plunger and barrel assembly of
the fuel injection pump is worn exces-
sively;
2. The governor spring is deformed or
loosened;
3. For abnormal operation of the fuel
injection pump, refer to Chapter 3 of
this Part to maintain the pump.
4
Fuel system
Ingression of air into the fuel system
Remove the air in the fuel pipeline.
5
Fuel supply
advance angle
The fuel supply advance angle is
insufficient.
Adjust the fuel supply advance angle
to 16°±1°
6
Fuel delivery
quantity
The fuel delivery error of cylinders is
out of specification.
Adjust the delivery unevenness of cyl-
inders to specified range: Nominal:
10%; Calibrated: 10%; Idling: 30%.
7
Intake pipe
Air filter
The air intake is not smooth.
Clean or replace the filter element
8
Valve
The intake and exhaust valve clear-
ance is inappropriate.
Adjust (Refer to Section 1, Chapter 3
of this Part)
9
Valve timing
The valve mechanism parts are worn
seriously.
Change the worn parts as required, and
adjust the valve timing:
Intake valve open Before upper dead
point
12
±
3
°
Intake valve closed After lower dead
point
38
±
3
°
Exhaust valve open Before lower dead
point
50
±
3
°
Exhaust valve closed After upper dead
point
14
±
3
°
10
Fuel injector
seat
There is air leakage from the sealing
surface between the seat and cylinder
head.
Remove the carbon deposit or tighten
the set bolts.
11
Cylinder head
Cylinder head
gasket
The cylinder head bolts are loosened;
There is air leakage from the cylin-
der head gasket.
The tightening torque for the cylinder
head bolts is (145
～
155)N.m;
Change the cylinder head gasket.
12
Piston ring
The piston ring is deposited with
carbon, jammed or worn.
Clean the carbon deposit or replace it
with new one (Refer to Section 4,
Chapter 2, Part II)
Summary of Contents for KM/4L22
Page 6: ......