Piper COMANCHE PA-24-180 Service Manual page 371

PIPER COMANCHE SERVICE MANUAL
7A-54. Fuel Injector.
7A5 5. Fuel Injector Mainterunce.
a. In general Little attenuon is required between injector overhauls. However. ui is recommended chat
the following items be checked during periodic inspection of the engine.
1.
Check tghtness and lock of all nud and screws which fasten the mlector to the engine.
2.
Check all fuel lines for ightness and evidence of leakage. A slight fuel samn adjacent to the air
bleed nozzles i nor cause for concern
3. Check throttie and mixture control rods and levers for righness and lock.
4.
Remove and clean the injector fuel inlet strainer at the firs 25 hour inspecton
and each 50
hour inspection thereafter. Damaged straner "O" rings should be replaced. Torque strainer to 65-70 inch
pounds.
b. Tests prove that gsoline which becomes stale due to prolonged storage absorbs oxygen rapidly
This sale oxidized gasoline acquires a very distnctive odor similar to vanish. causes rapid deterioraton
of
syntheric rubber pans, and also forms a gummy deposit on the internal metal prts.
This condinon,
however. does not occur dunng normal operation of the injector where fresh fuel us being constantly
circulated.
7A-56. Lubrication Of Fuel Injector.
a. There is very little need for lubrication of the injector in the field between regular overhauls.
However, rhe clevis pins used in connection with the throttle and manual mixture control levers should be
checked for freedom of movement and lubricaed, if necessary
b Place a drop of engine grade oil on the end of the throttle shaft in such a manner that it can wor;
into the throttle shaft bushings.
7A-57 Removal Of Fuel Injector.
a. Remove the lower cowling as described in paragraphs 7A-5 or 7A-8
b. Disconnect the throttle and mixture control cables at the injector unit.
c. Disconnect fuel lines at injector unit.
d. Remove ne in)ector from the engine sump by removing pal locknuts. nuts and wasners
e. Cut safety wire and remove bols attaching the air box to the injector unir.
7A-58 Preparation Of Fuel Injector For Shipping. Any unit taken out of service. or units being returned
for overhaul. must be flushed witr preserving oil (Specification
MIL-O-081. Grade 1010). using ne
following procedures:
a.
Remove plugs and drain all fuel from the injector. If available, applv 10 to 15 psi air pressure :o
the fuel inlet unui all fuel is discharged from the in!ector
b Replace piugs and appl rflushing oil filtered through a 10-micron filter at 13-15 psi co the :niector
fuel inlet until oil is discharged from rne outlet.
c. Replace fuel inlet snipping plug
POWER PLANT
ISSUED: 8/18/72
2 D13