Isuzu 4JA1 Workshop Manual page 216

6C – 34 FUEL SYSTEM
2. Release the nozzle tester handle so that in-line
pressure decreases.
Note:
The in-line pressure will decrease and needle
valve lift (as indicated on the dial gauge) will also
decrease a little.
040MV022.tif
3. Then, read the pressure gauge indication (second
nozzle opening pressure) the instant that the dial
gauge indicates the specified needle valve lift (usually
pre-lift + 0.05 mm).
Second Nozzle Opening Pressure
4JA1T(L)
040M100006
Pressure Mpa
2
(psi/ kg/cm )
25.5-27.0
(3768-3911/260-275)
Lift mm (in)
0.09 (0.0035)