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Does anyone have experience on calibrating the Sonex fuel level probe with MGL efis?

It's been several years since I did that. but there were no problems. I started with an empty tank, nose dragger, and added car gas in two gallon increments, recording the probe resistance at each level. I'm at 220 hours on the hobbs and I have considered doing it again. When I add a known amount of gas to a reading on the gage it doesn't add up exactly to the tenth. I don't fly below an hour in the tank so I'm not worried, just curious.

Just on a side topic do you run auto gas all the time? I thought the probes fall apart if auto fuel used? Ive stuck to avgas mainly as I love the accuracy of the level prob.

I had no isses with the calibration. Filled in 5 litre increments and wrote the numbers down so i dont lose them if my efis gets updated or reset.. has happened once already.

I run primarily auto gas and have had no problems with the probe. As I understand it, alcohol will destroy the probe. I run 91 octane unleaded fuel.

Oh ok... thanks for the clarification. I think I'll start testing auto fuel out then.

Like Bill, I only run auto gas, ethanol free. He tells me that when he has to add 100 LL the probe does not read correctly. I haven't had to do that. Evidently the resistance is different for the two fuels.

Hi Brett
I use the princeton (sonex) sender with MGL. Mostly I run 98 octane unleaded, using avgas only when I have to. My experience is that alternating between fuels does not make any difference whatsoever to the fuel gauge readings.
Steve
Sonex 892

Where did you find the instruction to record resistances at different fuel levels? It seems that I've read that somewhere, but now that I'm at that stage, I cannot find it.

BV

Does anyone know what the empty calibration numbers should be? On my MGL IEFIS ( Discovery Lite) it shows 2760 and when I added 15 litres of fuel it still shows 2760 so I aborted the calibration in search of help instead. The RDAC pull up resistor is on as per instructions. I am scratching my head wondering why it isn't changing with more fuel (98 Octane unleaded Methanol free) being added.

make sure the probe is grounded, my ground disconnected and it stopped working