Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 1459 / 1956

PAGE 1
Feb 28/07 7H13
77-20-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
TEMPERATURE
NOTE: In S/N’s 4636375 and up, engine data is collected by the Data Acquisition Unit (DAU) and is
displayed on the Multi-Function Display (MFD) and Primary Flight Display (PFD). See Electronic
Flight Instrument System, 34-20-00; 77-40-00, and 91-77-40 for more information.
1. Turbine Inlet Temperature (T.I.T.) Gauge
NOTE: Serial numbers 4636021 thru 4636374 incorporate the Transicoil Electronic Module Instrument
System (EMIS). See 77-40-00.
A. Description
This instrument is used to monitor the temperature of the exhaust gases as they leave the cylinders
(but before they enter the turbocharger turbine).
Although the gauge is adjustable, if it is found defective after checking with the troubleshooting
chart, it should be replaced. Replace any faulty leads to the gauge. Because the resistance of the
leads is critical for the proper operation of the gauge, use the same type and length of wire as the
original when replacing leads.
B. Troubleshooting
See Chart 1.
C. Gauge and Probe Cleaning and Inspection
CAUTION: DO NOT CONNECT OHMMETER ACROSS METER. IT WILL BURN OUT THE
MOVEMENT OF THE METER.
Unless mechanical damage is evident (broken glass, bent or broken pointer, or broken case) the
following checks should be performed before removing the instrument:
(1) Remove the engine cowling as necessary to expose the exhaust transition.
(2) Loosen the nut which secures the probe to the waste gate transition assembly. Remove the
probe.
(3) Check for a broken weld (at tip end) or a burnt off end. The measured resistance of probe
should be 0.73 ± 0.01 ohms. Clean the connections with steel wool.
(4) Disconnect the lead wires at the instrument and measure the resistance. Resistance with the
lead wires connected to probe should be 8 ohms. Clean connections with steel wool.
Trouble Cause Remedy
Gauge inoperative. Defective gauge, probe or Check probe and lead
wiring. wires for chafing, breaks or
shorting between wires
and/or metal structure.
Adjusting potentiometer Reset potentiometer.
turned off scale.
Fluctuating reading. Loose, frayed or broken Clean and tighten
electrical leads or faulty connections. Repair or
connections. replace defective wire.
CHART 1
TROUBLESHOOTING TURBINE INLET TEMPERATURE (T.I.T.) GAUGE