TM9-2815-202-34
4-40. FUEL INJECTOR ASSEMBLY REPAIR (Cont)
f. Testing
NOTE
Injectors that were disassembled
must pass all tests outlined below
prior to installation in engine.
Injectors which were removed from
engine should be checked prior to
any disassembly to avoid
unnecessary repair.
(1) Injector control rack freeness
(a)
(b)
(c)
(d)
(e)
Place injector in fixture (36).
Hold injector control rack (24) in
NO FUEL position. (Rack all the
way extended).
Using handle, depress follower to
bottom of its stroke.
Slowly release pressure on
handle while moving control rack
in and out until follower reaches
top of its travel. Injector passes
test if rack falls freely.
If rack binds, loosen injector nut,
turn tip, and then torque nut to
80 Ib-ft (108 N-m) for blued
components, 50 Ib-ft (68 N-m)
for nonblued components, or 65
Ib-ft (88 N-m) for mixed
components. Loosen and torque
nut a couple of times if
necessary. If rack still binds,
change injector nut. Finally, if
rack binds, disassemble injector
to eliminate cause of misaligned
parts or to remove dirt.
(2) Spray tip concentricity
(a)
(b)
(c)
(d)
Place injector in fixture (36).
Adjust dial indicator (37) to zero.
Rotate injector 360 degrees and note total runout as indicated on dial.
If total runout exceeds 0.008 inch, remove injector from fixture. Loosen injector nut,
center spray tip, and retorque nut. Recheck sprav tip concentricity. If, after several
attempts, spray tip cannot be positioned satisfactorily, replace injector nut.
4-232
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