Piper Cherokee Six - Manifold Pressure Gauge; Troubleshooting

PIPER
CHEROKEE
SIX
SERVICE
MANUAL
9-41.
MANIFOLD
PRESSURE
GAUGE.
9-42.
GENERAL.
The
manifold
pressure
gauge
is a
vapor
proof,
absolute
pressure
type
instrument.
Pressure
from
the
intake
manifold
of
the
engine
is
transmitted
to
the
instrument
through
a
line.
A
pointer
indicates
the
manifold
pressure
available
at
the
engine
in inches
of
mercury.
9-43.
TROUBLESHOOTING.
TABLE
IX-VIII.
MANIFOLD
PRESSURE
INDICATOR
Trouble
Cause
Remedy
Excessive
error
at
existing
barometric
pressure.
Excessive
error
when
engine
is running.
Sluggish
or
jerky
pointer
movement.
Pointer
shifted.
Line
leaking.
Defective
instrument.
Replace
instruments.
Tighten
line
connections.
Replace
instrument.
Dull
or discolored
marking.
Age.
Replace
instrument.
Incorrect
reading.
Moisture
or
oil
in
line.
Disconnect
lines
and
blow out.
9-44.
REMOVAL
AND
REPLACEMENT.
Refer
to
Paragraph
9-74
of this
section.
9-45.
TACHOMETER
INDICATOR.
9-46.
GENERAL.
The
tachometer
is
connected
to
the
engine
accessory
by a
flexible
cable
and
provides
an indication
of
crankshaft
speed
in
revolutions
per
minute.
The
instrument
has
a recording
mechanism
for
recording
the
time
that
the
engine
is
in actual
operation.
INSTRUMENTS
Issued:
8/17/72
2K23