Do not operate diesel fuel
injector nozzle tester without
shield. Fuel spray can penetrate
skin. Fuel oil entering blood
stream may cause serious
Place shield (43) on diesel fuel injector
nozzle tester (41). Operate pump
handle (40) with smooth even strokes
and record fuel injector needle valve
opening pressure (pop pressure).
Needle valve opens when fuel sprays
from tip. Pop needle valve several times
to purge air from system. Record test
gage (44) opening pressure. Final
needle valve opening pressure must be
Remove injector nut (11), spray tip (33),
needle valve (35), spring (16), spring
seat (15), spring cage (14), check valve
cage (17), and check valve (18) from
mounting pedestal (42).
After needle valve opening
pressure test is complete, continue
injector assembly [ref. step e.(13)].
(6) Needle Valve Holding Pressure
(a) Place fuel injector in fixture (38).
(b) Operate pump handle (39) to bring pressure up to 2200 PSI.
Pop fuel injector several times with popping handle (39) until no pressure is observed
on injector test fixture (41) before removing injector from test fixture to avoid fuel spray
as injector is removed from fixture.
(c) Close fuel shut off valve. Start timing when pressure reaches 2000 PSI and stop at
PSI. Minimum time is 20 seconds.
(d) If pressure drops in less than 20 seconds, check for leaks around spray tip, seal ring, and
END OF TASK
5-37 Install injectors (7083-7391, 7083-7396, and 7083-7399)
4-38 Install injectors (7083-7395 and 7083-7398)