Komatsu Galeo PC800-8 User Manual

6 PC800, 850-8
SEN00795-02 40 Troubleshooting
S-1 Starting performance is poor
General causes why starting performance is poor
• Defective electrical system
• Insufficient supply of fuel
• Insufficient intake of air
• Improper selection of fuel
• Coolant in exhaust pipe
aThe common rail fuel injection system (CRI) recognizes the fuel injection tim-
ing 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 Cracked EGR cooler (Coolant in exhaust pipe) Defective contact of valve, vale 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 Clogged feed pump gauze filter Stuck, seized supply pump plunger Defective injector Defective intake air heater system Defective alternator (regulator section) Defective alternator (generator section) Defective, deteriorated battery
Questions
Confirm recent repair history
Degree of use of
machine
Operated for long period
EE EE E
Starting performance
Became worse gradually
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Engine starts easily when warm
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Non-specified fuel is being used
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Replacement of filters has not been carried out according to Operation and Mainte-
nance Manual
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Engine oil must be added more frequently
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When engine is preheated or when temperature is low, preheating monitor does not
indicate normally (if monitor is installed)
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During operation, charge level monitor indicates abnormal charge (if monitor is
installed)
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Dust indicator is red (if indicator is installed)
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Air breather hole of fuel tank cap is clogged
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Fuel is leaking from fuel piping
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When priming pump is operated, it makes no reaction or it is heavy
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Starting motor cranks engine slowly
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Check items
While engine is
cranked with starting
motor
If air bleeding plug of fuel filter is removed, fuel does not
flow out
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If spill hose from injector is disconnected, little fuel spills
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When exhaust manifold is touched immediately after starting engine, temperature of
some cylinders is low
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Engine does not pick up smoothly and combustion is irregular
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There is hunting from engine (rotation is irregular)
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Blow-by gas is excessive
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Troubleshooting
Inspect air cleaner directly
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When EGR cooler outlet gas piping is removed, coolant containing antifreeze flows
out (*1)
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When compression pressure is measured, it is found to be low
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When air is bled from fuel system, air comes out
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Inspect fuel filter, strainer directly
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Inspect feed pump gauze filter directly
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Carry out troubleshooting for “Rail Press (Very) Low Error. (*2)”
See *2 for failure code.
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When a cylinder is cut out for reduced cylinder mode operation, engine speed does
not change
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When starting switch is turned to HEAT, intake air heater mount does not become
warm
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Is voltage 25 – 30 V between alternator terminal B and terminal E with
engine at low idle?
Yes
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No
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When specific gravity of electrolyte and voltage of battery are measured, they are low
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Remedy
Clean Replace Correct Replace Clean Correct Clean Clean Replace Replace Replace Replace Replace Replace

Komatsu Galeo PC800-8 Specifications

General

Brand	Komatsu
Model	Galeo PC800-8
Category	Excavators
Language	English