Yanmar 3TNV Series Service Manual page 58

(5) Fuel injection nozzle pressure inspection
Wear protective glasses when testing injection from the fuel injection valve. Never approach the
injection nozzle portion with a hand. The oil jetting out from the nozzle is at a high pressure to cause
loss of sight or injury if coming into careless contact with it.
(a) Injection pressure measurement
Model
3TNV82A TNV88 (CL )
3TNV82A TNV88 (VM )
4TNV94L 4TNV106(T)
[NOTICE]
As for the opening pressure of the brand-new fuel
nozzle, about 0.5Mpa(5kgf/cm) declines by the
engine operation for about 5 hours because of the
initial wear-out of a spring etc. Therefore, adjust
0.5MPa(5kgf/cm) higher than the standard value of
the above table when adjusting a new fuel nozzle of
a spare part.
Remove carbon deposit at the nozzle hole thoroughly
before measurement.
1) Connect the fuel injection valve to the high
pressure pipe of the nozzle tester.
2) Operate the nozzle tester lever slowly and read
the pressure at the moment when the fuel
injection from the nozzle starts.
3) If the measured injection pressure is lower than
the standard level, replace the pressure adjusting
shim with a thicker one.
Thickness of pressure adjusting shims
0.13, 0.15, 0.18, 0.4, 0.5, 0.8
Standard
2
MPa(kgf/cm )
19.6-20.6
(200-210)
21.6-22.6
(220-230)
Injection pressure adjustment
mm
The injection pressure is increased by approx. l.9 MPa(l9 kgf/cm
when the adjusting shim thickness is increased by 0.l mm.
43
2. Inspection and Adjustment
2
),