Piper ARCHER III Pilot Operating Handbook page 186

SECTION
7
DESCRIPTION & OPERATION PA.28.181.
ARCHER
III
7.7
INDUCTION
SYSTEM
The induction
system
incorporates
an
Avstar
RSA-5ADl
type
fuel
injector.
The injector
is
based
on
the
principle
of
differential pressure,
which
balances
air pressure against
fuel pressure. The regulated
fuel
pressure established
by
the
servo
valve
when applied across a
fuel control
(etting
system)
makes
the fuel
flow proportional to
airflow.
Fuel pressure
regulation by the servo valve
causes
a
minimal
drop
in fuel
pressure throughout the metering system.
Metering pressure
is
maintained above
most vapor
forming
conditions
while fuel inlet
pressure is
low
enough
to allow
use
of a diaphragm pump.
The
servo
system
feature also
checks
vapor
lock
and associated
starting problems.
The
servo regulation meters
fuel flow proportionally with airflow
and
maintains the
mixture
as
manually
set
for all engine
speeds.
The
fuel flow divider
receives metered
fuel
and
distributes
fuel to
each
cylinder fuel nozzle.
The induction airbox assembly contains
a valve that can open and
allow
airflow into
the
engine
in
the
event
of
blockage
of
the
primary induction
air
source.
The
air
provided through the alternate
air
source
is
heated,
which
will
also
provide induction
system
icing
protection. As this alternate air
source is
not
filtered,
the
primary air
source
should always
be used
for
takeofT.
Control
ofthe
alternate
air valve
is
through
a
lever located to the
right
ofthe
engine
control lever quadrant.
The
pilot
should read and
follow
the procedures recommended
in
the
I
engine Operator's
Manual
for
this
engine,
in
order
to obtain maximum
engine
efficiency
and
time between engine overhauls.
7.9 ENGINE CONTROLS
Engine controls consist
of
a throttle control and
a mixture control
lever.
These controls are located
on
the
control quadrant
on
the
lower
center
of
the
instrument
panel
(Figure
7-l)
accessible by the
pilot
and
the
copilot. The
control
cables are
teflon-lined to reduce
friction
and
binding.
The throttle lever is
used
to
adjust
engine
RPM.
The
mixture control
lever
is
used
to adjust
the
air to fuel ratio. The
engine
is shut down
by
the
placing
the
mixture control lever in
the
full
lean
position.
See
Section 4
of this
handbook
for
proper leaning procedure.
REPORT:
VB-2749
7-2
ISSUED: December 22,
20t7
REVISED: Janel7,20l9