Supplement Airplane Maintenance Manual
Cessna 172 with TAE 125-02-99 / -114
AMM-20-02
Rev. No:
Rev. Date:
Chapter:
Issue:
Issue Date:
Page:
Content:
20-AMM-71-02
3
06.11.2013
11
46
1
25.08.2014
Table 71-3a Troubleshooting / Engine runs roughly
Code
Indication
Code
Task/Check
Check by
Corrective Action
6
Engine
vibrates, runs
on three
cylinders
continously
6.1
Check injector
operation
Isolate faulty injector by running
the engine with one injector
connector removed at a time.
Engine will run best with the faulty
injector disconnected.
WARNING:
Do not run the
aircraft without an operator in
the cockpit. Do not approach
the engine bay while engine is
running
.
Perform subsequent tests only on
faulty injector
Check power supply to the injector
by inspecting wiring harness for
damage. Check condition of pins
at the injector.
Carefully
squeeze the pins on the
harness side connector to
improve contact. If possible, repair
wiring harness. Refer to repair
manual / contact TAE for
allowable repairs.
Replace injector
Refer to TAE Repair Manual
RM-02-02
6.2
Check fuel type and
quality
Contact TAE if wrong fuel type
has been used
6.3
Perform Leak Down
Test
Refer to Repair Manual for
detailed instructions and
limitations
Contact TAE
7
Engine
vibrates, runs
on three
Cylinders
intermittently
7.1
Check Crank signal
Connect FADEC Service Tool
using CAN interface kit. Both
ECU´s should deliver identical,
stable RPM display.
Proceed to Code 45, "Faulty
Crank Signal"
7.2
Check injector
operation
Isolate faulty injector by running
the engine with one injector
connector removed at a time.
Engine will run best with the faulty
injector disconnected.
WARNING:
Do not run the aircraft without
an operator in the cockpit. Do
not approach the engine bay
while engine
.
Perform subsequent tests only on
faulty injector
Check power supply to the injector
by inspecting wiring harness for
damage. Check condition of pins
at the injector.
Carefully
squeeze the pins on the
harness side connector to
improve contact. If possible, repair
wiring harness. Refer to repair
manual / contact TAE for
allowable repairs.
7.3
Check P-Rail sensor
signal
Connect FADEC Servie Tool while
performing ground run and
reproducing problem. Compare
"P-Rail" to "P-Rail Tar". If capable,
do so by gemerating graph.
Intermittent P-Rail sensor fault will
result in erratic pressure indication
and deviation from target value.
Proceed to Code 41, "Erroneous
Indication"
Engine runs roughly
Summary of Contents for Cessna 172
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