Starting Performance Is Poor - Komatsu Galeo PC800-8 Shop Manual

SEN00795-02
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.
Confirm recent repair history
Degree of use of
machine
Starting performance
Non-specified fuel is being used
Replacement of filters has not been carried out according to Operation and Mainte-
nance Manual
Engine oil must be added more frequently
When engine is preheated or when temperature is low, preheating monitor does not
indicate normally (if monitor is 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
When priming pump is operated, it makes no reaction or it is heavy
Starting motor cranks engine slowly
While engine is
cranked with starting
motor
When exhaust manifold is touched immediately after starting engine, temperature of
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 EGR cooler outlet gas piping is removed, coolant containing antifreeze flows
out (*1)
When compression pressure is measured, it is found to be low
When air is bled from fuel system, air comes out
Inspect fuel filter, strainer directly
Inspect feed pump gauze filter directly
Carry out troubleshooting for "Rail Press (Very) Low Error. (*2)"
See *2 for failure code.
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 25 – 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
6
Operated for long period
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
Causes
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PC800, 850-8