INSPECTION


NEEDLE VALVE / NOZZLE TIP

1.Wash the needle valve and nozzle tip clean in clean kerosene (cleaning oil) prior to reassembly.
2.Pull out the needle valve to approximately one third of its length, let go of it and see if it slides down by gravity. (Repeat this procedure a few times after turning the needle valve each time.)
3.If the needle valve fails to slide down by itself, wash it again and give it another check. Replace the needle valve and nozzle tip as a set.

INJECTION NOZZLE ASSEMBLY
Install the nozzle tester to the injection nozzle assembly and perform the following checks:
caution Prior to proceeding with the checks, bleed air from the injection nozzle by pumping the nozzle tester lever two or three times.

Valve Opening Pressure Check

1.Operate the nozzle tester lever at 1 to 2 seconds per stroke. Read the pressure when, after a gradual increase, the pointer deflects rapidly.
2.If the reading deviates from the specified standard value, disassemble the injection nozzle, clean and reassemble. Then, make necessary pressure adjustment using adjusting shims.
3.A shim thickness of 0.1 mm changes the valve opening pressure by 1,177 - 2,157 kPa. [The shim thickness necessary to change the pressure by 100 kPa is between 0.0045 mm and 0.0083 mm.]
4.If the reading still deviates after the adjustment, replace the injection nozzle assembly.

    Standard Value: 15,000 kPa

Check Spray Pattern

1.Inject fuel continuously by pumping the nozzle tester lever quickly (1 to 2 seconds per stroke)

    A: The spray is a straight and fine streak with a spray angle of approx. 10° (Acceptable)
    B: The angle of spray is too wide. (Unacceptable)
    C: The spray is out of the axial line. (Unacceptable)
    D: The spray breaks. (Unacceptable)
2.Disassemble, clean and recheck the injection nozzle assembly if necessary. If the problem still remains another check, replace the injection nozzle assembly.
3.Check that the injection nozzle does not dribble after injection.
caution Keep away from the fuel jet.

Oil Tightness Check

1.Slowly increase the nozzle internal pressure and maintain it at the specified test pressure of 12,749 - 13,729 kPa. In this condition, check that the injection nozzle does not start dribbling within 10 seconds.
2.If the dribbling begins in less than 10 seconds, disassemble, clean and recheck the injection nozzle assembly. If the problem still remains after another check, replace the injection nozzle assembly.