FUEL SYSTEM
7-30
3TNV88F Service Manual
Fuel Injectors
Adjusting Fuel Injector Pressure
The fuel injectors open when pressure reaches a
predetermined pressure threshold. They close
when the pressure is reduced below that threshold.
The pressure threshold can be adjusted by adding
or removing shims
.
1 – Fuel return passage
2 – Injector ID location
3 – Injector body
4 – Pressure adjusting shims
5 – Spring
6 – Spring seat
7 – Valve stop spacer
8 – Nozzle valve
9 – Nozzle body
10 – Nozzle case nut
Figure 7-52
The injection pressure will change by
approximately 275 PSI (1.9 MPa; 19 kgf/cm
2
) for
every 0.1 mm (0.004 in.) in shim thickness.
See the parts catalog for available shims.
NOTICE
Each pressure adjusting shim removed or added
changes the pressure threshold by approximately
275 PSI (1.9 MPa, 19 kgf/cm
2
). Adding adjusting
shims increases the threshold pressure. Removing
adjusting shims reduces the pressure threshold.
1. Disassemble the fuel injector assembly.
Disassembly and Inspection of Fuel Injectors
on page 7-28
2. Remove or add adjusting shims as needed.
3. Reassemble the fuel injector assembly.
Reassembly of Fuel Injectors on page 7-30
4. Retest the fuel injector.
. If the injector cannot be
adjusted to the appropriate pressure, discard
the fuel injector.
Reassembly of Fuel Injectors
1. Secure the injector in a soft-jawed vise with the
nozzle end up.
2. Reinstall the shims, nozzle spring, nozzle
spring seat, valve stop spacer, nozzle valve,
and nozzle body.
3. Reinstall the nozzle case nut. Tighten it to
specification.
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3TNV88F_SVM_A4.book 30 ページ 2012年7月26日 木曜日 午後6時4分