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TrueAirSpeed
03-08-2010, 09:14 PM
Rob, I'm a little ways from starting the engine, so the fuel tanks are empty. But the fuel tank display on the 4500 EFIS indicates the tanks to be full. I want to fix this so it indicates exactly what fuel is in the tanks (none). I've looked in the installation/user manual, but can't see where it addresses calibrating the 4500 and when I follow the steps outlined I get no where. Tell me I'm overlooking something simple and what that something is.

Thanks,

Terry
RV-7

AltonD
03-08-2010, 10:41 PM
Capacitance probes? If so, they will not work till you have established unusable fuel and set the zero fuel point on the convertes.

Floats: I can't help you there.

TrueAirSpeed
03-08-2010, 10:50 PM
Sorry, I should of mentioned that they are capacitance probes. I checked the sending units today and they both indicate "tanks empty."

Terry

Rob Hickman
03-09-2010, 09:16 PM
Where are you getting lost?

Steps To Calibrate a Tank:

Place the AF-3400/3500/4500 into Instrument Calibration mode. Use the [NEXT] button to scroll down to Tank 1 (Left Main) or Tank 2 (Right Main), Tank 3 Left Aux, Tank 4 Right Aux.
Verify that the Tank is Empty.
Enter the max size of the Tank in the Tank Size field.
Set the Audio On/Off Setting. If you set this to ON you will get an Audio warning if the fuel level is below the Red Low At setting.
Set the Instrument On/Off Setting. If you set this to ON the tank will be displayed.
Enter the number of calibration points; you must have at least two points. You could use four points (zero, ¼, ½, ¾, Full) or one point for every 2 gallons. Every calibration point must have a Quantity that is higher than the previous one.
Use [NEXT] to Scroll down to the tank calibration data. The calibration data is displayed in two columns, one for ground and one for flight. Use the knob button to switch between ground and flight data columns. The current AD_VALUE reading for the tank is displayed at the top of the table.
Starting at 0 Gallons press the [COPY] button or use the knob to record the current AD_Value to the correct fuel amount and attitude (ground or flight).
9. You will need to fill and record a reading for each attitude (ground and flight). If you have a tail wheel aircraft, the best way to do this is to record the ground data then lift the tail and record the flight data after the fuel reading has settled. Repeat this for each increment until the tank is full.

Press the [SAVE] button to save the data to permanent memory and [RETURN] to exit Tank Calibration.
CAUTION: Do not turn off power before pressing the save button and exiting the calibration menu.
Calibration Tips:
When lifting the tail you should set it on something, so the level you lift it to will be consistent. You should also wait until the reading stops changing before setting it.
Fuel tank sensors are not accurate when the tank is near full. Once you notice the reading not changing much or not corresponding with the rest of the readings during calibration the last few entries in the fuel calibration data should be set to the same value.
If the tanks do not consistently show full you should lower the digital value for the tank full data.
The fuel gauge will only show the digital fuel amount for the highest reading that the float changed with a plus sign indicating that the correct fuel amount is not known but is over the last reading. The analog gauge will show full for the last changing reading. It is normal for an 18-gallon tank to show 16+ when it is full. This indicates that the float stopped changing at 16 gallons and this is the highest fuel reading that can be detected by the float in the tank.

TrueAirSpeed
03-21-2010, 09:12 PM
Thanks Rob!

jachurch
05-30-2012, 08:52 PM
I am having trouble calibrating my fuel tanks. Aircraft is a Sportsman 2+2 with IO 390 engine
I get to the calibration page ok and see Instrument Calibration 1. Tank size through 6. Units.
I don't see 7. Num Cal Points of any AD Value displayed. How do I get these displayed so I can do the calibration. It is almost as if
some admin has these locked so they can't be changed. I have a few gals remaining will the calibration numbers show up anyway
without zero fuel. Or maybe it's the fuel probes. I've looked in the Admin settings and don't see anything.
Hopefully Rob will reply to this thread or someone who's been there. HELP

I found the answer which was simple: I was trying to calibration from the left side the FLIGHT EMS need to do it form the right side the Engine EMS.
Hope this helps others.