Assemble the fuel injector in a clean, well lighted work
area isolated from the rest of the shop.
Before assembling injector, all injector parts shall be
dipped in engine fuel per Military Specification MIL-J-
5624 or Federal Specification VV-F-800.
Make sure that the guide pins on intermediate disc (5)
bottom are inserted properly into matching holes on top
of nozzle (6).
(1) Install nozzle (6), intermediate disc (5), pres-sure
spindle (4), and pressure spring (3) and
appropriate number of shims (2) in holder (7).
(2) Screw retainer nut (1) onto nozzle holder (7).
Tighten nut (1) to 63 lbs ft (85 Nm) torque.
(3) To test the fuel injector assembly, proceed as
Use clean filtered diesel fuel, per Military Specification
MIL-J-5624 or Federal Specification VV-F-800, in nozzle
Loosely connect injector to be tested
to nozzle tester (Table 2-1) using test
line listed in Table 2-1. Pump nozzle
testers handle several times to flush
air from test line. Tighten all
Keep hands away from nozzle spray. Spray can
puncture the skin allowing test oil to enter the blood
stream. Consult a physician at once if spray punctures
Pump nozzle testers handle up and
down quickly (approximately six to
eight times a
second). Fuel should spray from injector nozzle tip in an
atomized mist (see Figure 6-27) and
the nozzle should emit a sharp high-
If nozzle does not chatter, flush nozzle
by pumping tester handle rapidly.
Repeat step c.
several times to flush air from the
nozzle. Open pressure gauge valve.
observing pressure gauge. Nozzle
should open at 2, 600 + 120 - 0 psig
(17, 927 + 827- O0 KPa).
Do not wipe the nozzle tip with the fingers as this will
tend to draw the fuel present in the sac hole through the
orifices and falsely indi-cate a leak and rejection of a
good valve. Hold a wiper lightly against the tip of the
Bleed off pressure until nozzle valve
seats. Using a lint free cloth, wipe
nozzle tip dry.
Figure 6-27. Fuel Injector Spray Pattern