Garmin G3X upgrade - being told fuel pressure cannot be connected to EIS

[Elliot Ness]

We're in the process of upgrading the standard panel to a Garmin G3X with GEA24 EIS but the company undertaking the work in Europe say they are unable to connect the fuel pressure sensor to the EIS as turbo engines with differential fuel pressure sensors are not supported.

I've shared another post from this forum showing where other installations have the Garmin fuel pressure sensor located and I'm being told installation of the additional sensor is not part of the STC.

Would be grateful for any information on the installation of the Garmin pressure sensor linked to the G3X on a M20M as it would be disappointing to not link fuel pressure to the new system and need to retain the old gauge.  

[carusoam]

Welcome aboard Mr. Ness!

I thought you were from the Chicago area… but that was a century ago…. 

Let me invite @donkaye to the conversation…  (fuel pressure sensor question)

Don has a Bravo and is familiar with many of Garmin’s products…

 

Big G has a good customer service guy @TrekLawler…. See if you can find him…. Often seen cruising BT.

Best regards,

-a-

[donkaye]

8 minutes ago, carusoam said:

Welcome aboard Mr. Ness!

I thought you were from the Chicago area… but that was a century ago…. 

Let me invite @donkaye to the conversation…  (fuel pressure sensor question)

Don has a Bravo and is familiar with many of Garmin’s products…

 

Big G has a good customer service guy @TrekLawler…. See if you can find him…. Often seen cruising BT.

Best regards,

-a-

I have the MVP50, so don't have any additional information to contribute.

[carusoam]

6 minutes ago, donkaye said:

I have the MVP50, so don't have any additional information to contribute.

Thank you Don!

I have made two errors that weren’t memory related today… 

Best regards,

-a-

[PilotX]

Please check in with @Warren he is handling my G3X install and I believe I have the GEA24 but I could be mistaken. Should be able to help.

[rbp]

My M29M G3x displays fuel pressure and didn’t need to retain the old gauge.

[Davidv]

When I installed the G3X on my previous Bravo they removed the factory fuel pressure sensor and installed the one specified by garmin.  It’s a slightly different setup on the engine but your installer should see this in the STC docs for the Bravo.  I can’t recall the specific brand sensor they used in place of the factory original but it may have started with a K?

[rbp]

every time I switch tanks on my Garmin EIS-equipped Bravo, I check the fuel pressure, so I am 100% sure I have it  

[oregon87]

The fuel pressure systems on turbocharged aircraft typically require upper deck pressure to be monitored to accurately display fuel pressure.  To really simplify, the equation is as follows:

Fuel pump pressure - upper deck pressure = displayed fuel pressure

Without the injector nozzles referencing upper deck pressure, they would remain at ambient pressure, which would not allow fuel to flow to the engine.  As such, the upper deck pressure needs to be subtracted from the indication to display true pump pressure.  As such, whatever instrumentation being used to monitor fuel pressure would need some type of differential input to reference signals from the two sources.

Edited December 2, 2022 by oregon87