g3x + eis and fuel gauges

[Ulysse]

my fuel gauges were quite accurate before the g3x + eis installation. Now the left tank always shows 38 gal and almost never moves (I once saw the gauge suddenly move when the tank was almost empty). The right one instead shows 28gal when full but moves with fuel consumption. My installer says he calibrated the system during installation. Is this a coincidence or is there an issue with the garmin system ?
 

[Niko182]

3 minutes ago, Ulysse said:

my fuel gauges were quite accurate before the g3x + eis installation. Now the left tank always shows 38 gal and almost never moves (I once saw the gauge suddenly move when the tank was almost empty). The right one instead shows 28gal when full but moves with fuel consumption. My installer says he calibrated the system during installation. Is this a coincidence or is there an issue with the garmin system ?
 

Do you have cies senders or the stock ones?

[squeaky.stow]

I don’t know how to link to other threads here, but @PMcClure posted in December that the stock Mooney fuel senders are not compatible with the G3X.

Google  mooneyspace fuel quantity indication g3x  and you will find the post.

[Ulysse]

1 minute ago, Niko182 said:

Do you have cies senders or the stock ones?

The stock ones

[Ulysse]

1 minute ago, squeaky.stow said:

stock Mooney fuel senders are not compatible with the G3X

Thank you. I found the post. I hope I will not have to replace the senders.

[Niko182]

Just now, Ulysse said:

Thank you. I found the post. I hope I will not have to replace the senders.

I mean if you want accurate fuel readings, it seems like thats going to have to be the case.

[Warren]

While I haven't installed the GEA24 with traditional fuel senders, the manual does say that they are compatible.  Make sure your installer configured them correctly and that the senders are working.

From the G3X installation manual:

Select the installed fuel quantity probe configuration: Voltage or Digital.
The GEA 24 supports four fuel quantity inputs (FUEL 1 through 4), any of which can be
used with a resistive, analog or digital fuel quantity sensor. Reference Table C-6 for input
selection nomenclature for approved interfaces.
CAUTION
Resistive fuel probes must be configured as ‘Voltage’ interfaces per Table C-6. If a resistive
probe is incorrectly configured as ‘Resistive’, the fuel gauge indication may appear to be valid
on the display, however it will not be accurate in all operating conditions.

It should support what you are trying to do.

You can also check the resistance of the sensor when empty and while filling to make sure the float is moving and the sender is working.

[ArtVandelay]

While I haven't installed the GEA24 with traditional fuel senders, the manual does say that they are compatible.  Make sure your installer configured them correctly and that the senders are working.
You can also check the resistance of the sensor when empty and while filling to make sure the float is moving and the sender is working.

You need to insure the senders give stable readings through the entire range of movement of the float. No jumping of readings, which will be ignored my analog gauges but picked up by digital circuitry.

[PMcClure]

Garmin came out with a bulletin that stock gauges are not compatible with the G3X.

 

 

Edited June 21, 2021 by PMcClure

[Ulysse]

don't they have a fix for it now?

[Warren]

On 6/20/2021 at 11:02 PM, Ulysse said:

don't they have a fix for it now?

Yes.  They swap out resistors and move to a voltage sense circuit vs. a resistance sense. There is a bulletin outlining the details.

 

[Ulysse]

That is excellent news. Thank you! Is this document available publicly or only to installers? I am curious to see what the modification involves

[Warren]

This is a Garmin dealer bulletin.  I don’t think it is publicly available.

However, your dealer should be able to help - Garmin Service Bulletin 2134 Rev A.

If installed prior to April 2021 as a resistive fuel sender setup, this fix should be covered under warranty.

Edited July 3, 2021 by Warren
Added Garmin Service bulletin and warranty information

[PT20J]

Here it is:

https://www.garmin.com/en-US/aviationalerts/modification-of-gea-24-resistive-fuel-probe-interface/

Note the date is April 26, 2021, so your installer should have been aware of it.

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