Appendix D
© 2018 Avco Corporation. All Rights Reserved
Page 514
November 2018
TEO-540-C1A Engine Maintenance Manual
Fault ID
426
Fault Group
54
Fault Name
[FAULT: low fuel injector pressure
delta]
Fault
Description
Low fuel injector pressure delta fault
Fault Lamp
FFL
Root Cause
This fault indicates the fuel injector pressure delta is consistently below the minimum
allowable threshold
Troubleshooting Steps
1.
Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? If
yes, go to step 2. If no, go to step 6.
2.
While engine is running, set aux fuel pump switch to on. Is fault still active? If yes, go to step 3. If no,
go to step 6.
3.
Are there any active or logged fuel pressure sensor, MAP sensor, or aux fuel pump faults? If yes, go to
troubleshooting procedure for related fault. If no, go to step 4.
4.
Inspect airframe fuel pump, fuel filter, fuel supply lines, fuel return lines, engine fuel pump, fuel rail,
fuel pressure regulator, and fuel manifold return lines for damage or obstructions. Replace any
components that are damaged or obstructed. Run the engine in accordance with the engine and aircraft
maintenance manuals. Is the fault active? If yes, go to step 5. If no, go to step 6.
5.
With engine running, using the FST, monitor engine fuel pump and fuel rail pressure. Is fuel pump and
fuel rail pressure within specified limits in accordance with Appendix A of the
TEO-540-C1A Engine
Installation and Operation Manual
? If pump pressure is out of limits, replace fuel pump. If fuel rail
pressure is out of limits, replace fuel pressure regulator. Then go to step 6. If both are within limits,
contact Lycoming Engines.
6.
Clear Service faults using the FST by following the steps outlined in the “Access the Field Service
Tool” section in Appendix C or the latest revision of
SSP-118.
Fault ID
427
Fault Group
54
Fault Name
[FAULT: Low fuel pressure with
aux pump active]
Fault
Description
Low fuel pressure with Aux Pump
active
Fault Lamp
FFL
Root Cause
This fault indicates the fuel pump pressure is low with auxiliary pump active.
Troubleshooting Steps
1.
Run the engine in accordance with the engine and aircraft maintenance manuals. Is the fault active? If
yes, go to step 2. If no, go to step 6.
2.
While engine is running, set aux fuel pump switch to on. Is fault still active? If yes, go to step 3. If no,
go to step 6.
3.
Is there an active aux fuel pump output fault? If yes, go to corresponding troubleshooting procedure. If
no, go to step 4.
4.
Inspect airframe fuel pump, fuel filter, fuel supply lines for proper operation, damage or obstructions in
accordance with aircraft maintenance manual. Replace any components that are not operating properly,
damaged or obstructed. Run the engine in accordance with the engine and aircraft maintenance
manuals. Is the fault active? If yes, go to step 5. If no, go to step 6.
5.
With engine running, using the FST, monitor engine fuel pump and fuel rail pressure. Is fuel pump and
fuel rail pressure within specified limits in accordance with Appendix A of the
TEO-540-C1A
Installation and Operation Manual
? If pump pressure is out of limits, replace the fuel pump. If fuel
rail pressure is out of limits, replace fuel pressure regulator. Then go to step 6. If both are within limits,
contact Lycoming Engines.
6.
Clear Service faults using the FST by following the steps outlined in the “Access the Field Service
Tool” section in Appendix C or the latest revision of
SSP-118.
