FUEL SYSTEM
7-28
3TNV88F Service Manual
Fuel Injectors
Figure 7-46
4. Pump the operating lever of the tester slowly,
observing the pressure reading at the point
where the fuel injector begins spraying fuel
.
for injector ID location.
See Test and Adjustment Specifications on
page 7-6 for correct pressure readings.
Note: The opening pressure of a new fuel
injector will be approximately 0.5 MPa (5
kgf/cm
2
, 72.5 PSI) higher than one that
has been operated for five hours or
longer.
5. Pump the operating lever slowly to hold the
pressure steady at a point just below the
opening pressure and hold it for 5 seconds.
Observe the injector to see that it is sealing
properly and is not “dripping”. If fuel leaks from
the return line fitting, check that the nozzle case
nut is tight. Service or replace the injector if fuel
continues to leak from either the return line
fitting or nozzle.
6. Pump the operating lever more rapidly to
repeatedly “pop” the injector and observe the
spray pattern. The pattern should be a very fine
uniform spray
If a dripping or an
uneven pattern is seen
, service
or replace the injector.
Figure 7-47
Figure 7-48
If the fuel injector fails any of these tests, it should
be serviced or replaced as necessary. If the
pressure is outside specified limits, adjust the
pressure.
See Adjusting Fuel Injector Pressure
Disassembly and Inspection of Fuel
Injectors
NOTICE
Never use a steel wire brush to clean fuel injectors.
Damage to the nozzle and other components is
likely to result.
1. Clean carbon from used injectors using clean
diesel fuel. Hardened deposits or varnish can
be cleaned using a brass wire brush.
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3TNV88F_SVM_A4.book 28 ページ 2012年7月26日 木曜日 午後6時4分