Extra care should be used in handling the fuel
injector nozzle in order to prevent damage to the
nozzle tip. A scratch or a burr could cause needle
leakage or spray distortion. Keep dirt from the
orifices in the nozzle tip which could damage
engine components or cause spray distortion.
Make sure that you wear eye protection at all times during
testing. When fuel injection nozzles are tested, test fluids
travel through the orifices of the nozzle tip with high
pressure. Under this amount of pressure, the test fluid
can pierce the skin and cause serious injury to the
operator. Always keep the tip of the fuel injection nozzle
pointed away from the operator and into the fuel collector
5P-4150 Nozzle Testing Group.
(8) 5P-7448 Adapter
(9) Fuel injector nozzle
(10) 6V-2170 Tube
(11) 1U-8857 Extension
(12) 8S-2270 Fuel Collector
(13) 8T-5313 Filter
Do not use dirty test fluids when you test fuel injection
nozzles. Also, do not test fuel injection nozzles unless
you have the correct service tools. The use of dirty test
fluids and the use of incorrect service tools will result In
damage to fuel injection nozzles.
Connect the fuel injector nozzle (9) to the tooling that is
shown in Illustration 57.
The spray from the fuel injector nozzle must be directed
into the 1U-8857 Extension (11) and the 8S-2270 Fuel
Refer to the table in Specifications, "Fuel Injector
Nozzles" for the correct pressure settings. If the
opening pressure is not within the range of the setting
which is given in the table, the fuel injector nozzle must
Use clean 6V-6068 Calibration Fluid when the fuel
injector nozzles are tested. The calibration fluid is
equivalent to SAE J-967 (ISO 4113) oil.
Close the gauge protector valve. Close the shutoff
valve. Open the pump isolator valve. In order to flush
the fuel injector nozzle, operate the nozzle tester for 10
to 15 strokes at a rate of approximately 60 strokes per
Open the gauge protector valve. Slowly increase the
pressure until the valve in the fuel injector nozzle opens.
Note the highest pressure indication on the dial indicator
before the pointer moves to 0 kPa (0 psi). This highest
pressure indication is the opening pressure of the fuel
injector nozzle. The opening pressure is defined when
the valve needle (16) is lifted from the valve seat.
Refer to the table in Specifications, "Fuel Injection
Nozzles" for correct pressure settings. If the opening
pressure is not within the range of the setting that is
given in the table, the fuel injector nozzle must be
Back Leakage Test
Connect the fuel injector nozzle (9) to the tooling. Refer
to Illustration 57 for more information.
Position the fuel injector nozzle so that the direction of
the fuel spray is into the 1U-8857 Extension (11) and
the 8S-2270 Fuel Collector (12).
Pump the pressure to about 1030 kPa (150 psi) below
the opening pressure of the fuel injector nozzle. Refer
to Specifications, "Fuel Injection Nozzles" for the correct
setting of the opening pressure. Release the handle.
When the pressure begins to decrease, note the time
that is required for the pressure to decrease to
approximately 0 kPa (0 psi). If the fuel injector nozzle is
not defective, the time will not be less than 5 seconds or
more than 45 seconds.
If the time that is required for the pressure to decrease
to 0 kPa (0 psi) is less than 5 seconds, too much fuel is
leaking around the valve needle. Replace the fuel