Handling Reduced Cylinder Mode Operation; Handling No-Injection Cranking Operation - Komatsu WA250-6 Shop Manual

SEN03836-01
Handling reduced cylinder mode
operation
a Reduced cylinder mode operation means to
run the engine with the fuel injectors of 1 or
more cylinders disabled electrically to reduce
the number of effective cylinders. The pur-
poses and effects of this operation are as fol-
lows.
1. This operation is used to find out a cylinder
which does not output power normally (or,
combustion in it is abnormal).
2. When a cylinder is selected for the reduced
cylinder mode operation, if the engine speed
and output do not change from the normal
operation (all-cylinder operation), that cylinder
has 1 or more defects. The possible defects
are as follows.
Compression leakage through cylinder
q
head gasket
Defective injection
q
Defective piston, piston ring, or cylinder
q
liner
Defective valve mechanism (Moving valve
q
system)
Defect in electrical system
q
3. Since the common rail fuel injection system
controls the injector of each cylinder electroni-
cally, the operator can perform the reduced cyl-
inder mode operation easily with switches to
find out a defective cylinder.
a The reduced cylinder mode operation is
set from the service mode of the machine
monitor.
For details, see "Special functions of
machine monitor (EMMS)", "5. Reduced
cylinder mode operation function".
32
30-110

Handling reduced cylinder mode operation

Handling no-injection cranking
operation
1
a No-injection cranking means to crank the
engine with the starting motor while all the
injections are stopped electrically. The purpose
and effect of this operation are as follows.
When a machine or engine has been stored for
q
a long time, implementing the no-injection
cranking before starting the engine lubricates
the engine parts and thus prevents its seizure.
a The no-injection cranking operation is set from
the service mode of the machine monitor. For
details, see "Special functions of machine
monitor (EMMS)", "6. No-injection cranking
function".
110 Testing and adjusting, Part 1
WA250, 250PZ-6
1