Isuzu 4JA1 Workshop Manual page 209

REASSEMBLY AND ADJUSTMENT PROCEDURE
1
First nozzle opening pressure adjustment
2
Full needle valve lift confirmation
3
Pre-lift confirmation
4
Second nozzle opening pressure
confirmation
5
Second nozzle opening pressure
adjustment
6
Final inspection
First nozzle opening pressure adjustment
Nozzle needle valve full-lift
Nozzle needle valve pre-lift
Nozzle pressure
4JA1T(L) 1st Stage
2nd Stage
NOTE: Only 4JA1L can perform adjustment of a nozzle.
Adjust the first nozzle opening pressure using the shim.
Confirm the full needle valve lift in accordance with the
closed method.
Confirm pre-lift in accordance with the closed method.
CAUTION:
If not as specified, replace the nozzle assembly, lift
piece, pins and spacer using the nozzle service kit.
Confirm the second nozzle opening pressure in accordance
with the closed method.
Adjust the second nozzle opening pressure using the shim.
Confirm the condition of the fuel spray with the nozzle and
nozzle holder assembled.
0.25 mm (0.0098 in)
0.04 mm(0.0016 in) at 20 MPa (2901 psi, 204 kg/cm
19.1 MPa (2759 psi, 194 kg/cm
25.5-27.0 MPa (3768-3911 psi, 260-275 kg/cm
FUEL SYSTEM
2
)
2
)
2
)
6C – 27