Piper Comanche PA-24 Service Manual page 491

PIPER COMANCHE SERVICE MANUAL
7 A-H. Fuel Injector.
i A·5 5. Fue! IDjector Maintenance.
I.
In genen.i. little attennon is required between injector overhauls.
HOWCveT.
it is recommended that
the following i,ems be checked during periodic mspection of the enline.
I. Check ",hmess and lock of &II nulf and
sc~
which futeD the injector
'0
the engine.
2. Check &II Nel lines for ,,,illness and evidence of leak.,e. A 51i1/ll Nelluin adjacen' to the alf
bleed nozzles iJ not cause for concern
l. Check throttle and mixtllre control rods and lcyers for tightness and lock.
... Remove and clean the injector fuel inlet srraincr
at
the flf'St 2' hour inspection and each 50
hour inspection thercUter. Damaged strainer "0" rings showd b. replaced. Torque "'aIRer to 65·70 inch
pounds.
b. Tens prove 'hat gasoline which becomes stale due to prolonged sto ..... absorbs oxygen rapIdly
This stale OXidized gasoline acquU'C:S a very distinctive odor sunilar to varnISh. causes rapid deterioration of
syntheril: rubtm' puts. and also fanns a gummy deposit on the internal metal parts. This (ondiaon,
however. does not occur durine: nonnal open non of the IJljector where fresh fuel is being constAntly
circulated.
7A-56.
Lubrication Of Fuel Inj.OIor.
a. There is very little need for lubrication nf the injector in the field betWeen regular overc.auls.
However. rhe cleY1.1 pms used in connection with the throttle and. manual mlXNre conC'Ollevers shou.ld 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 throttie shaft bushings.
;:\-'i
Removu Of Fuel Injector.
1.
Remove the lower cowling
a.s desc:=ibed In paugt':l.phs 7.4.0-5 or
j
A-8
b. Disconnect the thron:ie and mixtUre control c:l.bles at the injector unit.
c. Disconnect fuel linn :l.t injector unit.
d. Re:no\'c thc Injector irom the c:lgine sump lJy removing pallocknuu. nuts and wasners
e. CUt safety wire
i.ft~
removc bolts an:aching the
au
box to thc injector
Unit.
i:\-58. Preparation Of Fuel Injector For Shipping. :\ny unit taken out of service. or unitS being returned
for overhaul. must be fiushed
Wltit
preserving oil (Speclfica.tlon
~lL'()-6081.
Grade lOla)'
uSing
tne
follOWing procedurn:
a.
Remove plugs and drain ill fuel from the injector. If lvallable, ap?l'" 10
[0
15 ?5i air ?ressure:o
[.&le fuel inlet until all fueils discharged from [he in.lector
b Replace plugs and ap?ly rlushing oil filtered through a. IO-micron filter It 13-15 psi
~o
the :nJector
fuel inie! until oil is discharged from tne outlet.
c. RepLace fuel mlet snlppang plug
2
013
POWER PLANT
ISSUE D: a/la/72