Manifold Pressure Gauge; Manifold Pressure Indicator Troubleshooting; Tachometer Indicator Troubleshooting - Piper PA-24 Comanche Service Manual

PIPER COMA!'iCHE SERVICE MA!'il"AL
• I 1-45. \1anifold Pressure Gauge.
11·~fI.
General. The manifold pressure gauge is a vapor proof. absolute pressure type instrument. Pre...... ure
from the Intake manifold of the engine is transmitted to the instrument through a line. A pointer indicate . . .
the manifold pre...sure available at the engine in inches of mercury.
11-47. Removal And Replacement. Refer to Paragraph I
I·U~
of this section.
I
J -~~.
Troubleshooting.
TABLE XI-\·II\. MA:'\IFOLD PRESSURE t;\DICATOR
•
Trouble Cause
Remedy
Excessive error at existing
Pointer shifted. Replace instrument-
ba rornetric pressure.
Excessive error when
Line leaking.
Tighten line connections.
engine is running.
Sluggish or jc:rky poi mer Improper damping adjustment. Adjust damping screw.
rnovernent.
Broken or loose cover Virbration or excessive Replace glass and reseat
gla.......
pressure. case.
Dull or di ...colored Age. Replace instrument.
luminous marking....
Incorrect reading. Moisture or oil in line. Disconnect lines and blowout.
11-49. Tachometer Indicator.
11·50. 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.
II-51. Removal And Replacement. Refer
to
Paragraph 11-18 of this section.
11-5~.
Troubleshooting.
•
ISSl'EO: 8/18/72
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