Service manual

FUEL INJECTION NOZZLE
Reassembly
The fuel injection nozzle is assembled in the
reverse order of disassembly.
1. Insert the adjusting shims, spring and spring
seat in the nozzle holder, mount the nozzle
valve stop plate with the pin, insert the nozzle
assembly and tighten the nozzle case nut.
2. Use the nozzle holder when tightening the case
nut to 28.8
- 32.5 ft-lb (39 - 44 N-m, 4 - 5 kgf.m).
Opening Pressure Adjustment
Mount the fuel injection nozzle on the nozzle tester
(Figure 7-10, (1)) and use the handle to measure
injection opening pressure. If it is not at specified
pressure, add or remove adjusting shims to
increase or decrease the pressure, see
Specifications on page 7-2 for fuel injector opening
pressures.
Note: Adjusting by 0.004 in (0.1 mm) results in
a change in the injection opening
pressure of about 290 psi (2
MPa,
20 kgf/cm2)
COO1 335
Figure 7-1 0
Injection Test
After adjusting the nozzle to the specified opening
pressure, check the fuel spray condition and make
sure the nozzle does not leak.
1. Check the injection spray condition, by
operating the nozzle tester lever once or twice
per second to check for abnormal injection.
Correct
Spray from each nozzle hole is uniform. -
Spray is fully atomized (no streams of fuel).
Start and stop of injection is "sharp" (a
clean chatter sound should be heard).
Poor
0001337A
Excessive difference in spray angle.
lncomplete atomization
Causes - lncomplete opening/closing of
injection nozzle.
Figure 7-1 1
2. Check that the nozzle tip is not leaking after two
or three injections, then gradually increase the
pressure up to 200 psi (1.38
MPa;
14.06 kg/cm2). Maintain the pressure for 5
seconds and make sure that no oil is dripping
from the opening pass the nozzle.
MP Series Service Manual YANMAIP.