Operation
and
Maintenance
Manual
for
WP2.1C/WP3.9C
Series
Marine
Diesel
17
Remove the high-pressure fuel pipe for the first cylinder; join a pipe to a thin
glass tube and connect it with the first cylinder delivery valve holder of the injection
pump. Set the speed control lever to the maximum delivery position and bleed off the
air in the fuel system. (Turn the crankshaft till there are no air bubbles in the fuel
flowing out of the glass tube). Then turn the crankshaft slowly and watch attentively
for the rise of the fuel level in the glass tube. Stop turning the crankshaft at the
beginning of the rise of fuel level which implies the beginning of the fuel delivery to
the first cylinder. Check to see if the mark of fuel delivery to the first cylinder on the
flywheel aligns with the timing pointer inside the flywheel housing. If it does not,
readjust in the following procedure. Slacken the bolts which fasten the injection pump
onto the connecting flange. Turning the injection pump with its top towards the
cylinder block results in the increase in the fuel delivery advance angle, and vice
versa.
4.3 Adjustment of Nozzle Opening Pressure
Dismount the fuel injector from the cylinder head and mount it on the injector
tester for checking and adjusting. Actuate the pump handle and watch the indication
of pressure. At the time of injection starting, the pressure should be within the range
as specified in Section , Main Engine Data. The fuel spray should be uniform and
Ⅰ
the puffing sound of injection should be short and clear.
The opening pressure of the P-type injector can be adjusted by choosing from
different adjusting shims of the thickness in the range from 1.0 mm to 2.0mm. The
gauge step is 0.01mm. Most of the injector manufactures use the shims of the
thickness from 1.7mm to 1.9mm. Before reassembling the injector, clean the nozzle
valve and the adjusting shim. Care must be taken not to scratch the matching faces.
After attaining the specified pressure, remount the lock nut and check for the opening
pressure again.
4.4 Adjustment of Lubricating Oil Pressure
Pay frequent attention to the lubricating oil pressure. The normal oil pressure
ranges from 200 kPa to 500 kPa. The adjustment of lubricating oil pressure should be
carried out after the engine gets warm (when the lubricating oil temperature is around
80 ). Dismount the sealing nut from the adjusting screw on the oil filter. Turn the
℃
adjusting screw to adjust oil pressure. Screw in or out the adjusting screw to increase
or decrease the oil pressure. After adjustment, put on the sealing washer and then
tighten the sealing nut.
