Engine Does Not Pick Up Smoothly - Komatsu Galeo PC800-8 Shop Manual

SEN00795-02
S-3 Engine does not pick up smoothly
General causes why engine does not pick up smoothly
• Insufficient intake of air
• Insufficient supply of fuel
• Defective condition of fuel spray
• Improper selection of fuel
• Controller is controlling in derate mode (limiting injection rate (output) because
of an error in electrical system)
• EGR valve is stuck open
(There is much EGR gas and intake of air is insufficient)
Confirm recent repair history
Degree of use of
Operated for long period
machine
Engine pick-up suddenly became worse
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
Dust indicator is red (if indicator is installed)
Air breather hole of fuel tank cap is clogged
Rust and water are found when fuel tank is drained
Fuel is leaking from fuel piping
When priming pump is operated, it makes no reaction or it is heavy
When exhaust manifold is touched immediately after starting engine, temperature of
some cylinders is low
Blue under light load
Color of exhaust
gas
Black
When engine is cranked, abnormal sound is generated around cylinder head
When engine is cranked, interference sound is generated around turbocharger
High idle speed under no load is normal, but speed suddenly drops when load is applied
There is hunting from engine (rotation is irregular)
Blow-by gas is excessive
Inspect air cleaner directly
Carry out troubleshooting for "EGR Valve Servo Error. (*1)". See *1 for failure code.
When compression pressure is measured, it is found to be low
Inspect valve clearance directly
When turbocharger is rotated by hand, it is found to be heavy
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
*1: Failure codes [CA1228] and [CA1625]
*2: Failure codes [CA559] and [CA2249]
12
Causes
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Remedy
40 Troubleshooting
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PC800, 850-8