Komatsu 114E-3 Series, Руководство по ремонту, Страница: 264 / 342

SEN00458-01 40 Troubleshooting
6
114E-3 Series
S-1 Starting performance is poor 1
*1: Code [559/CA559] and code [2249/CA2249] in E-mode
*2: Code [2265/CA2265] and code [2266/CA2266] in E-mode
General causes why starting performance is poor
q
Defective electrical system
q
Insufficient supply of fuel
q
Insufficient intake of air
q
Improper selection of fuel
a
The common rail fuel injection system (CRI) recognizes
the fuel injection timing electrically. Accordingly, even if
the starting operation is carried out, the engine may not
start until the crankshaft revolves 2 turns at maximum.
This phenomenon does not indicate a trouble, however.
Causes
Clogged
air
cleaner
eleme
nt
De
fective con
tact
of valve and valve seat
W
orn piston ring, cylin
der
Clogged
air
breathe
r hole of fuel t
ank cap
Leaking or clogged fuel pipin
g, entry of air
Clogged
fuel filter
, element
S
tuck, seized supply pump plunger
De
fective electr
ic lif
t pump
Defec
tive i
njector
De
fective int
ake a
ir
heater system
De
fective alte
rnator
(reg
ulato
r section)
De
fective alte
rnator
(gener
ator sectio
n)
De
fective or dete
riorated ba
ttery
Questio
ns
Confirm recent repair history
Degree of use of machine Operated for long period
E E E
Starting performance
Became worse gradually
Q w w Q
Engine starts easily when warm
w w
Non-specified fuel is being used
Q Q Q
Replacement of filters has not been carried out according to Operation and Mainte-
nance Manual
w w Q Q
Oil must be added more frequently
w
When engine is preheated or when temperature is low, preheating monitor does not
indicate normally (if installed)
w
During operation, charge level monitor indicates abnormal charge (if monitor is
installed)
w w
Dust indicator is red (if indicator is installed)
w
Air breather hole of fuel tank cap is clogged
w
Fuel is leaking from fuel piping
w Q
Starting motor cranks engine slowly
w
C
heck items
While engine is cranked
with starting motor,
If air bleeding plug of fuel filter is removed, fuel does not
flow out
w Q
If spill hose from injector is disconnected, little fuel spills
w
When exhaust manifold is touched immediately after starting engine, temperature
some cylinders is low
w
Engine does not pick up smoothly and combustion is irregular
Q Q w
There is hunting from engine (rotation is irregular)
Q w Q Q
Blow-by gas is excessive
w
T
roublesh
ooting
Inspect air cleaner directly
q
When compression pressure is measured, it is found to be low
q q
Inspect fuel filter, strainer directly
q
Carry out troubleshooting according to “No-pressure feed by supply pump (*1)” in E-
mode
q
Carry out troubleshooting according to “Abnormality in electric lift pump (*2)” in E-
mode
q
When a cylinder is cut out for reduced cylinder mode operation, engine speed does
not change
q
When starting switch is turned to HEAT, intake air heater mount does not become
warm
q
Is voltage 20 – 30 V between alternator terminal B and terminal E with
engine at low idle?
Yes
q
No
q
When specific gravity of electrolyte and voltage of battery are measured, they are
low
q
Remedy
Clean
Replace Replace
Clean
Corr
ect
Replace Replace Replace Replace Replace Replace Replace Replace