Komatsu ecot3 PC300-8, Руководство по ремонту

Страница: 846 / 1035

SEN02634-02 40 Troubleshooting
6
PC300, 350-8
S-1 Starting performance is poor 1
*1: Failure codes [CA559] and [CA2249]
*2: Failure codes [CA2265] and [CA2266]
General causes why starting performance is poor
• Defective electrical system
• Insufficient supply of fuel
• Insufficient intake of air
• 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.
Cause
Cl
og
ged
air cleaner element
Def
e
c
tive
cont
act
of
v
a
lv
e and
valve
seat
W
o
rn
pist
on r
ing,
c
y
linder
Cl
og
ged
air breat
h
er
hole of
f
u
el
t
a
nk
c
a
p
Leaking or
clogged
fuel
piping,
ent
ry of
ai
r
Cl
og
ged f
uel f
ilt
er/
s
tr
ai
ner
S
tuc
k,
seize
d
sup
p
ly
pum
p plunger
Def
ec
tiv
e elec
tr
ic
lif
t pump
Def
ec
tiv
e inj
ec
tor
Def
e
c
tive int
a
k
e
air heat
er
sy
st
em
Def
e
c
tive alt
e
rnat
or (regulat
o
r
s
e
ct
io
n)
Def
e
c
tive alt
e
rnat
or (generat
or sect
ion)
Def
e
c
tive or det
e
riorat
ed bat
te
ry
Q
ues
ti
ons
Confirm recent repair history
Degree of use of
machine
Operated for long period
E E E
Starting perfor-
mance
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
Engine oil must be added more frequently
w
When engine is preheated or when temperature is low, preheating monitor does not
indicate normally
(if monitor is 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
Check it
em
s
While engine is
cranked with start-
ing 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 of
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
roubl
e
s
hoot
ing
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 for “Rail Press (Very) Low Error.” See *1 for failure code.
q
Carry out troubleshooting for “Power Lift Pump Error.” See *2 for failure code.
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
Cl
ea
n
Replace Replace Cl
ea
n
Correct Cl
ea
n
Replace Replace Replace Replace Replace Replace Replace