Fuel level calibration 2nd try failed

blueflyer

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Jun 15, 2012
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123
I have a D120 and resistive fuel sender. I have the sensor set to resistive (#1) in the system. I have tried 2 different resistive fuel senders. Senders are compatible with Dynon. Both times the calibration failed. The reading stay at a certain value for about 10 gallons before the sensor value will increase. Then it will stay at the next value for about 10 gallons. It always tells me it didn't sense that 2 gallons were added, so I hit the yes button. I am at a loss of what to try next. Any ideas.
 

Dynon

Dynon Staff
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Jan 14, 2013
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That fundamentally means that the system isn't seeing the sensor move until you're at 10 gallons. The number that you're seeing moves with the sensor. So most likely, the sensor isn't physically moving in the tank.
 

mmarien

Murray M.
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Dec 26, 2009
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Saskatoon SK CAN
I had cork screw type float sender in my Glasair and it didn't move for the first 40 litres.  :-?

I also had to shake the plane after adding to get it to move and then let it settle before pressing the add button. It worked OK flying because of the engine vibrations kept it from sticking. Except I had 40 litres I couldn't use as it went from 40 litres to zero.

I ended up installing a capacitive type sender. It accurately reads to the last few litres. :)
 

blueflyer

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Jun 15, 2012
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Am I supposed to have a resistor attached to the wire coming from the D120?  I do not.  Would that affect the sensor working as it should with the D120?  What size resistor should I put in (I know I can look that up, but I am being lazy asking that).

I only have one fuel tank and the sender is hooked up to pin 20 (orange/brown wire)
 

Dynon

Dynon Staff
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Not sure what you're asking blueflyer. Resistive fuel tank senders are themselves resistors. You don't have to add any other resistance to them. If their resistance isn't changing, we don't register a change in the fuel level.
 

blueflyer

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Jun 15, 2012
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you answered my question. I began to think I needed a resistor placed in the line which powers my resistive type fuel senders. thanks for the clarification.
 
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