Piper Navajo PA-31 Service Manual page 546

PIPER NAVAJO SERVICE MANUAL
q. Connect the battery ground wire at the battery.
r. Turn on the fuel valve; open the throttle full and turn on the electric fuel pump and
check the fuel lines for leaks.
s. Install the access plates on the engine nacelle and the cowling per Installation of
Engine Cowling, Section VIII.
t. Perform an engine operational check.
8B-11. ENGINE SHOCK MOUNTS. (Refer to Engine Shock Mounts, Section VIII.)
8B-12. TURBOCHARGER. (Refer to Turbocharger, Section VIII.)
8B-13. INDUCTION SYSTEM AIR FILTER. (Refer to Induction System Air Filter,
Section VIII.)
8B-13a. ALTERNATE AIR DOOR. The alternate air door is incorporated in the induction
air tube between the air filter and the turbocharger compressor inlet. The purpose of the
door is to provide a source of air should there be an air stoppage through the filter. The
following should be checked during inspection:
a. Door seal must fit flush with interior of duct opening.
b. Actuate the door to determine that it is not sticking or binding.
c. A minimum of a 9 pound force is required to open the door against the magnetic
force. The 9 pound force is to be applied at the center of the door and perpendicular to the
door surface, using a force scale. Make several checks to insure 9 pound test is consistent. If
the 9 pound force test fails, check to insure both magnetic catch plates make full contact
with alternate air door. Full contact can be obtained by bending the magnetic catch bracket
as needed.
d. Check the cockpit control cable for free travel.
e. Check that when the control knob in the cockpit is full in, the cable is adjusted to
maintain .062 to .125 inch clearance between cam and alternate air door in the fully closed
and magnetically latched position.
f. Check security of magnetic catch attachment per the latest revision of Piper Service
Bulletin 479.
8B-14. FUEL INJECTOR. (Refer to Fuel Injector, Section VIII.)
8B-15. FUEL AIR BLEED NOZZLE. (Refer to Fuel Air Bleed Nozzle, Section VIII.)
8B-16. IGNITION SYSTEM MAINTENANCE.
8B-17. MAGNETO.
Revised: 9/24/81
POWER PLANT
2K24