Piper Navajo PA-31 Service Manual page 488

3. Check throttle and mixture control rods and levers for tightness and
lock.
4. Remove and clean the injector fuel inlet strainer at the first 25 hour
inspection and each 50 hour inspection thereafter.
Damaged strainer "O" rings
should be replaced.
b. Tests prove that gasolinewhich becomes stale due to prolonged storage ab-
sorbs oxygen rapidly.
This stale oxidized gasoline acquires a very distinctive
odor similar
to varnish, causes rapid deterioration
of synthetic rubber parts,
and also forms agummydepositon
the internal metal parts. This condition, how-
ever, does not occur during normal operation of the injector where fresh fuel is
being constantly circulated.
8-41. LUBRICATION.
a. There is very little need for lubrication of the injector in the field between
regular overhauls.
However, the clevis pins used in connection with the throttle
and manual mixture control levers should be checked for freedom of movement
and lubricated,
if necessary.
b. Place a drop of engine grade oil on the end of the throttle shaft in such a
manner that it can work into the throttle shaft bushings.
8-42. REMOVAL OF FUEL INJECTOR.
a. Remove the lower cowl panel as described in paragraph 8-4.
b. Disconnect the throttle and mixture control cables at the injector.
c. Disconnect the fuel inlet, flow, pressure anddischarge lines at the injector.
d. Remove tha pal-lock nuts and nuts securing the injector to the engine.
e. Loosen the two clamps securing the hose that is between the injector and
injector inlet plenum.
f. Disconnect the necessary hoses and lines to the injector inlet plenum, so
that the plenum may be moved aft far enough to allow the injector to be removed.
8-43.
PREPARATION FOR STORAGE. Any unit taken out of service, or units
being returned
for overhaul,must
be flushed with preserving oil (Specification
MIL-O-6081, Grade 1010), using the following procedure:
a. Remove plugs and drain all fuel from the injector.
If available, apply 10
to 15 psi air pressure
to the fuel inlet until all fuel is discharged from the in-
jector.
b. Replace plugs and apply flushing oil filtered through a 10-micron filter at
13-15 psi to the injector fuel inlet until oil is discharged from the outlet.
Reissued: 10/12/79
POWER PLANT
PIPER NAVAJO SERVICE MANUAL
2114