Fuel Level Calibration - MGL iEFIS Lite & RED Capacitive Probe

Electrical and Panel
1

I’m in process of calibrating my fuel level sender and need some guidance. My components are: G3 iEFIS Lite, RDAC & RED Capacitive Fuel Probe. Sonex with a 20 gallon tank.

100LL - Avgas

All grounds go directly to the engine block

I have confirmed that the fuel level probe is putting out a voltage as follows when removed from the RDAC:

20 gallons – 4.7 volts

16 gallons – 4.4 volts

12 gallons – 4.0 volts

When I go onto the fuel level calibration page for RDAC 1, Fuel Tank 1 – the EFIS displays a current raw reading of 3908 – no matter what the fuel level is. I’ve confirmed that the RDAC PU voltage is off – switched it back and forth to make sure. I even moved the fuel probe sending wire (yellow out of the RED box) to the fuel level 2 input – in case something was wrong with fuel level 1 circuitry. No change – still reads 3908 regardless of the fuel level.

I did notice that the current raw reading on the calibration page is 92 when the sending wire is removed from the RDAC.

Any thoughts as to what I should try next?

Bill

N67WX

2

PM sent …

3

I had similar issues and took me months to sort it out.

The instructions had me calibrating zero fuel and then change the mode to 1S. You need to calibrate empty after changing to 1S mode, not before.

At least that was what worked in my case.

1 Like
4

Murray,

You might be on to something here - I’ll give that a try.

Thanks,

Bill

1 Like