N941WR
Legacy Member
For three years I was chasing a fuel level issue with my right tank and finally found and fixed the problem.
I would start up the plane and the EFIS would report the correct amount of fuel. Then, on some flights, while cruising along fat dumb and happy the right fuel level would drop down to zero, a few gallons at a time. Continue cruising and the level would come back up to the proper level.
I was 100% certain I had a bad ground wire. Multiple times over the past few years I have replaced the wires, checked the ground, etc. Every test flight indicated the proper fuel level and multiple times I was confident I had slayed this issue.
Then, on one flight, about an hour and fifteen minutes after I took off the fuel level dropped down, came back up, dropped down, etc. for the remainder of the flight. On the return flight, after an hour plus, the fuel gauge again started acting up.
Then it hit me, my capacitance sender (I purposely didn't give you all the info on my configuration until this point.) must be having an issue after it warms up.
A quick call to Dynon had a new sending unit in the mail. The next week found me back in the hangar installing the new sending unit.
After multiple long flights with the new sending unit installed, I'm happy to report that my fuel gauge is accurate and stable.
When I built my plane, the capacitance fuel level sensors was something I didn't know much about but after doing some research, I knew they were something I must have.
After nine years of flying with them, even with the intermittent issue I described above, I am always impressed at how accurate they are. If my fuel levels indicate I will need 10.3 gallons, the pump will stop on 10.3 gallons.
They are so accurate, that it was two years before I calibrated my fuel flow and to this day, I rely on the tank readings more than the fuel flow readings.
I realize that the capacitance senders will not read the same level with auto fuel and that's OK with me because I have yet to put any auto fuel in my plane.
When and if they ever come out with an unleaded alternative to 100LL, I will have to recalibrate my senders and that is a small price to pay for the accuracy of these things!
I would start up the plane and the EFIS would report the correct amount of fuel. Then, on some flights, while cruising along fat dumb and happy the right fuel level would drop down to zero, a few gallons at a time. Continue cruising and the level would come back up to the proper level.
I was 100% certain I had a bad ground wire. Multiple times over the past few years I have replaced the wires, checked the ground, etc. Every test flight indicated the proper fuel level and multiple times I was confident I had slayed this issue.
Then, on one flight, about an hour and fifteen minutes after I took off the fuel level dropped down, came back up, dropped down, etc. for the remainder of the flight. On the return flight, after an hour plus, the fuel gauge again started acting up.
Then it hit me, my capacitance sender (I purposely didn't give you all the info on my configuration until this point.) must be having an issue after it warms up.
A quick call to Dynon had a new sending unit in the mail. The next week found me back in the hangar installing the new sending unit.
After multiple long flights with the new sending unit installed, I'm happy to report that my fuel gauge is accurate and stable.
When I built my plane, the capacitance fuel level sensors was something I didn't know much about but after doing some research, I knew they were something I must have.
After nine years of flying with them, even with the intermittent issue I described above, I am always impressed at how accurate they are. If my fuel levels indicate I will need 10.3 gallons, the pump will stop on 10.3 gallons.
They are so accurate, that it was two years before I calibrated my fuel flow and to this day, I rely on the tank readings more than the fuel flow readings.
I realize that the capacitance senders will not read the same level with auto fuel and that's OK with me because I have yet to put any auto fuel in my plane.
When and if they ever come out with an unleaded alternative to 100LL, I will have to recalibrate my senders and that is a small price to pay for the accuracy of these things!
