Service manual

FUEL INJECTION NOZZLE
I Cleaning
Note: Before inspecting or assembling, all
components must be washed with clean
diesel fuel or standard cleaning solution
l
and completely clean and free of
contaminants.
1. Clean carbon from outside of nozzle body using
a brass brush.
I
2. Clean nozzle opening with small length of
deburred steel 0.0055 in. (0.14 mm) wire
(Figure 7-6, (1)).
0001331
Figure 7-6
3. Clean nozzle seat with cleaning spray.
Note: An ultra sonic cleaner can be used to
effectively clean the injector body and
inner components after loose material is
removed.
Inspection
1. lnspect oil seal surfaces for abnormal scratches
or wear, replace as necessary.
2. lnspect nozzle body for scratches and wear on
nozzle body and tip. Replace the nozzle if the
nozzle sliding surface or seat are scratched or
abnormally worn.
3. Rotate and slide the nozzle to check for smooth
movement
(Figure 7-8), replace the nozzle
assembly if the nozzle does not slide smoothly.
YANM'R. MP Series Service Manual
0001 332A
Figure 7-7
4. lnspect the nozzle valve stop for scratches
and/or wear at the sealing surfaces on both
sides. Check for abnormal wear at stop plate
center hole where it makes contact with the
nozzle
(Figure 7-8, (I)), replace if worn.
0001333b
Figure 7-8
5. lnspect the nozzle spring, replace it if
deformed, or the surface is scratched or rusted.
0001530
Figure 7-9
6. lnspect the nozzle oil sealing surface for
scratches
and/or wear, replace it if wear is
excessive.