Komatsu PC200-8M0, Shop Manual

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600 Troubleshooting of engine (S-mode)
S-1 Startability is poor
40-600
6
PC200, 200LC, 220, 220LC-8M0
SEN06140-00
S-1 Startability is poor
*1: Failure codes [CA559] and [CA2249]
General causes why startability 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) controls the fuel injection timing
electrically. Accordingly, even if the engine is cranked properly, the engine
may not start until the crankshaft rotates two turns under the most disadvan-
tageous condition. This phenomenon does not mean a problem, however.
Cause
Clog
ged
a
ir cl
eane
r el
ement
Defective cont
act
o
f valve wi
th val
v
e
se
at
W
o
rn piston ring
o
r cylin
der
Clog
ged
a
ir
b
reather hol
e in fu
el t
a
nk ca
p
Lea
kage
or
clog
ging
o
f
fuel
pi
ping
o
r ai
r in
the
fuel
p
ipin
g
Clog
g
in
g of fuel
filter
S
tuck or seized
sup
p
ly pnmp pl
uge
r
Defective inj
e
cto
r
Defective int
a
ke
air
heater
system
Defective alterna
to
r (regulator
section)
Defective alterna
to
r
(ge
nerator section)
Defective or deterio
ra
te
d batte
ry
Ques
tions
Check recent repair history.
Machine opera-
tion hours
Operated for long period
E E E
Starting perfor-
mance Became worse gradually
Q w w Q
Engine starts easily when warm.
w w
Fuel other than specified one is used
Q Q Q
Filters are not replaced as indicated in the Operation and Maintenance Man-
ual.
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 proper functioning of preheating system.
w
During operation, charge level monitor indicates abnormal charge.
w w
Dust indicator indicates a red zone
w
Air breather hole in fuel tank cap is clogged.
w
Fuel leaks from fuel piping.
w Q
If priming pump is operated, no resistance is felt or it is heavy.
w Q
Starting motor cranks engine slowly.
w
Check items
When engine is
cranked with
starting motor, Even if air bleeding plug in fuel filter head is removed, fuel
does not flow out.
w
If spill hose from injector is disconnected, little fuel spills.
w
When exhaust manifold is touched immediately after starting engine, temper-
ature of some cylinders is low.
w
Engine does not pick up smoothly and combustion is irregular.
Q Q w
Engine hunts.
Q w Q
Blowby gas is excessive
w
T
roubl
eshoo
ti
ng
Check air cleaner.
q
When compression pressure is measured, it is found to be low.
q q
When air is bled from fuel system, air comes out.
q
Check fuel filter.
q
Perform troubleshooting for "Supply pump pressure low error” according to
failure code (*1).
q
Even if a cylinder is cut out, engine speed does not change.
q
Even if 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
when engine is running at low idle speed? Yes
q
None
q
Specific gravity of electrolyte and voltage of battery are low.
q
Remedy
Cl
ean
Re
place
Re
place
Cl
ean
Re
p
a
ir
Re
place
Re
place
Re
place
Re
place
Re
place
Re
place
Re
place