Opening Pressure
- Remove fuel injection pipes from injector nozzles and pump. When removing fuel spill tube nut, hold nozzle holder body with a wrench to prevent it from rotating with nut.
- Remove injection nozzle assembly from cylinder head. Mount nozzle on nozzle tester and pump tester handle to bleed nozzle. See Fig 1 .
- Operate nozzle tester at a rate of more than 60 strokes per minute and read gauge pressure. The reading will increase gradually with pointer oscillating while nozzle is spraying. Injection pressure is the pressure at which the pointer starts to oscillate.
- Service limit for new injectors is 1920-2033 psi (135-143 kg/cm2 ), used injectors 1778-1920 psi (125-135 kg/cm2 ). If test pressure is outside limit, nozzle needs to be cleaned and adjusted.
- Injector pressure can be adjusted with shims that are available in varying thicknesses. A change of .0016 in. (.04 mm) will change injector pressure 68 psi (4.8 kg/cm2 )