Komatsu SAA6D114E-3 - Starting Performance Is Poor

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 element Defective contact of valve and valve seat Worn piston ring, cylinder Clogged air breather hole of fuel tank cap Leaking or clogged fuel piping, entry of air Clogged fuel filter, element Stuck, seized supply pump plunger Defective electric lift pump Defective injector Defective intake air heater system Defective alternator (regulator section) Defective alternator (generator section) Defective or deteriorated battery
Questions
Confirm recent repair history
Degree of use of machine Operated for long period EE E
Starting performance
Became worse gradually Qww Q
Engine starts easily when warm ww
Non-specified fuel is being used QQ Q
Replacement of filters has not been carried out according to Operation and Mainte-
nance Manual
wwQQ
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)
ww
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 wQ
Starting motor cranks engine slowly w
Check items
While engine is cranked
with starting motor,
If air bleeding plug of fuel filter is removed, fuel does not
flow out
wQ
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 QQ w
There is hunting from engine (rotation is irregular) QwQ Q
Blow-by gas is excessive w
Troubleshooting
Inspect air cleaner directly q
When compression pressure is measured, it is found to be low qq
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
Correct
Replace Replace Replace Replace Replace Replace Replace Replace