Chapter 3 Fuel Injection Equipment
4. Adjustment of Fuel Injection Pump and
Governor
4LHA Series
4-4 Plunger pressure
test
(1) Mount the pressure gauge to the delivery retainer
of the cylinder to be tested.
9.81~8.83(100-.90)
MPa(kgf/cm)
5
seconds
(to drop 0.98(10)MPa(kgf/cm')
Max.
pressure gauge reading
98.1(1,000)
MPa(kgf/cm)
Connecting
screw dimensions
M12x
1.5
(2) Set the governor control lever in the stop position,
operate the injection pump at about 200 rpm, and
make
sure
that
the pressure gauge reading is
49.0(500)MPa(kgf/cm) or more. All the time lightly
move the control rack towards
full
throttle
(drive
side).
Replace
the plunger if the pressure does not reach
this value.
(3) Immediately release the rack after the pressure has
stopped injection.
At the same time, check to see
that
oil is not leak-
ing from the delivery retainer or fuel injection
piping,
and
that
there is no extreme drop in pres-
sure.
4-5
Delivery
valve
pressure
test
(1) Perform the plunger pressure test in the same way,
bringing the pressure to about 11.8(120)/MPa
(kgf/cm), and then stopping injection.
Pressure
gauge
(2) After the pressure has risen to the above value,
measure
the time it takes to drop from 9.81 - 8.83
(100 - 90) MPa (kgf/cm).
If the pressure drops faster than this, wash the
delivery valve, and retest.
Replace
the delivery
valve
if the pressure continues to drop rapidly.
4-6
Adjusting
injection
volume
(uniformity
of each
cylinder)
The
injection volume is determined by the fuel injec-
tion pump rpm and rack position.
Check
and adjust to
bring it to the specified value.
4-6.1
Measuring
injection
volume
(1) Preparation
Set
the pump rpm, rack position and measuring
stroke to the specified value and measure:
Pump
RPM
See
separate service data
Pump
rotating direction
Right looking from drive side
Rack
indicator
scale
reading
See
separate
service
data
(2) Measuring injection volume
Measure
the injection volume at the standard
stroke,
and adjust as follows if it is not within the
specified
value.
Measuring
stroke
Specified
injection volume
at standard rack position
Nonuniformity of cylinders
See injection pump
service data
4-62
Adjustment
of
injection
volume
(1) Adjustment of injection volume: loosen the two
nuts on the flange of the plunger barrel, and
turn
the plunger barrel to the
right
or
left.
(2) Measure the injection volume of each cylinder
again.
Repeat
this process until the injection volume for
every cylinder is the same,
(within
the specified
limit)
(3) After completing the measurements, retighten
the nuts of plunger barrel flange.
Tightening torque
25.5-27.5(2.6-2.8)N(kgf) m
(4) If not aligned
with
the match mark, make a new
match mark.
3-2-34
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