Starting Performance Is Poor - Komatsu 114E-3 Series Shop Manual

SEN00458-01
S-1 Starting performance is poor
General causes why starting performance is poor
Defective electrical system
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Insufficient supply of fuel
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Insufficient intake of air
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Improper selection of fuel
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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.
Confirm recent repair history
Degree of use of machine Operated for long period
Starting performance
Non-specified fuel is being used
Replacement of filters has not been carried out according to Operation and Mainte-
nance Manual
Oil must be added more frequently
When engine is preheated or when temperature is low, preheating monitor does not
indicate normally (if installed)
During operation, charge level monitor indicates abnormal charge (if monitor is
installed)
Dust indicator is red (if indicator is installed)
Air breather hole of fuel tank cap is clogged
Fuel is leaking from fuel piping
Starting motor cranks engine slowly
While engine is cranked
with starting motor,
When exhaust manifold is touched immediately after starting engine, temperature
some cylinders is low
Engine does not pick up smoothly and combustion is irregular
There is hunting from engine (rotation is irregular)
Blow-by gas is excessive
Inspect air cleaner directly
When compression pressure is measured, it is found to be low
Inspect fuel filter, strainer directly
Carry out troubleshooting according to "No-pressure feed by supply pump (*1)" in E-
mode
Carry out troubleshooting according to "Abnormality in electric lift pump (*2)" in E-
mode
When a cylinder is cut out for reduced cylinder mode operation, engine speed does
not change
When starting switch is turned to HEAT, intake air heater mount does not become
warm
Is voltage 20 – 30 V between alternator terminal B and terminal E with
engine at low idle?
When specific gravity of electrolyte and voltage of battery are measured, they are
low
*1: Code [559/CA559] and code [2249/CA2249] in E-mode
*2: Code [2265/CA2265] and code [2266/CA2266] in E-mode
6
Became worse gradually
Engine starts easily when warm
If air bleeding plug of fuel filter is removed, fuel does not
flow out
If spill hose from injector is disconnected, little fuel spills
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Yes
No
Remedy
40 Troubleshooting
1
Causes
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114E-3 Series