RV12 Fuel tank readings

[richardsmi]

Based in the UK with aD180 in an RV12. Just approaching 10 hrs from new. Have now played with K factor and getting fuel flow-rate readings which relate well to actuals, and the readings for fuel in tank seem right too. BUT how do I correct the figures which show I have negative fuel left in the tank etc. which must have been generated during the time before the K factor was corrected?
I have read through the Installation and User Manuals more than once and have found nothing relevent. Help required please.

 

[jakej]

Maybe you could fill up the tanks and add the negative quantity to the full amount ?

Jake J

 

[dynonsupport]

Page 10-2 of the D180 Pilot's user's guide covers this.

Go to the EMS menu, then FUEL

Press FULL if you have full tanks, or ADD to add a specific amount.

Note you need to do this every time you add fuel to the plane. The fuel computer has no way to know how much you added (the floats in the tanks are not accurate enough). Even if your K factor is perfect, you'll still end up with negative numbers once you burn more than a tank of fuel if you never tell it you added any.

There is an option in the system to allow it to detect that you added fuel while off and remind you to add it to the computer. Not sure if Van's has this turned on with the RV-12.

 

[richardsmi]

Thank you for your guidance, however the fuel tank 'gauge' is reading correct levels. I have been using the ADDING process and I do have the reminder set up for when I do add fuel.
It is the extra information in the EMS pages which show a negative amount.
As there can never be a negative amount in the tank there must be some way of amending this in what is a sophisticated system without throwing the Tank readings out??

 

[dynonsupport]

All the fuel computer knows (fuel remaining, fuel used) is how much fuel has moved through the sensor, and how much you've told it you've started with. So, if you're getting "negative" fuel, simply reset it to correct next time you know the state of your tank (when you fill it). If you have your FULL preset setup, that's a "one click" deal. The amount of fuel "added" as far as the fuel computer is concerned will be high when you do this, but that doesn't really mater. Once you have the quantities matched between the actual tanks senders and the fuel computer, they should stay in sync provided you remember to hit the FULL button when you fill up, or use the add feature when you don't but do put some fuel in. Also note that if adding the the number of gallons that you've physically put into the tank doesn't roughly match the amount it would take the fuel computer to also read full after a fill, that you might need to adjust the K-factor per the procedure in the manual.

If that's still not too clear, give us a call. A 3 minute phone call will probably be an easier way to explain the subtleties of how the fuel computer works.

 

[richardsmi]

Thank you, I follow the logic as to how I come to have "negative fuel remaining" and the K factor is now set so that amount used is pretty close to expectations and also judging from the "spy holes" on the tank.
You use the words " simply set it to correct next time you use it"
That is just what I want to do but haven't read what the process is to "set it to correct" other than telling it it is full when the tank has been refilled.
Is there a 'Set to Correct' procedure, that I have missed or am I just being Thick??

 

[dynonsupport]

Thank you, I follow the logic as to how I come to have "negative fuel remaining" and the K factor is now set so that amount used is pretty close to expectations and also judging from the "spy holes" on the tank.
You use the words " simply set it to correct next time you use it"
That is just what I want to do but haven't read what the process is to "set it to correct" other than telling it it is full when the tank has been refilled.
Is there a 'Set to Correct' procedure, that I have missed or am I just being Thick??

We'd be happy to explain this better, interactively, in a brief phone call with Dynon Tech Support - 425-402-0433.

 

[richardsmi]

Thanks guys for your support.
I have with, your assistance, got to a position where the tank gauge is reading correctly and now the "Fuel remaining" also makes sense.
I ended up go through the Tank Full routine and played about adding and subtracting litres so that I understood how they worked together.
When I first posted I hadn't really explored what was available on the D180 and was concerned I would foul it up if I went exploring without knowing the consequences.