Low Fuel Pressure Indication

Also, if I am testing fuel pressure on a mechanical gauge with the engine not running, then the gauge and Garmin panel pressure should match, right?

The fine filter is getting plugged up.

Rotax has "referenced" their fuel injectors. That means the opening time is referenced to fuel pressure, with lower pressure the ECU opens the injector longer to get the correct amount of fuel injected.

Clearly there are limits to this,,,and I guess you are definitely getting too low.

simple things to do while away are

change all the filters

try Avgas

change the fuel pressure valve

Scott,

Yes, with engine off the fuel pressure on a mechanical gauge should match the readout on the G3X.  This is not a problem with the fine filter - if as you have indicated the pressure sender is in front of the fine filter.  In that case a clogged fine filter would raise the indicated pressure.  With all you have said, I’m thinking this is a problem with the pressure sender or possibly the garmin engine information module (Garmin GEA-24).  Get a mechanical gauge hooked up to verify the pressure sender and readout are correct.   

See photos