Navman fuel computer calibration...

Hi All,

Connected up a Navman fuel computer to a Navman 5505i tracker a few weeks ago, and filled up after my first long run. The Dorset trip we did in June was 94 miles or thereabouts for me, and the fuel computer said I had used 117l. filled up at the weekend, and she only took 92l.

Went into calibration mode, entered the 92l for fillup and thought all would be well. Then went out, and all weekend, the computer was showing a consumption figure, but always negative:] . Whilst I am happy to produce petrol from my engine:D moneyis more likely to grow on trees, so what have I done wrong when calibrating?

Guess will have to reset it next time, refill again and start over. But, can't see that I did anything wrong, unless I should not have told the computer I filled the tank prior to calibrating it?

Cheers

Neil

one problem i have had with fuel computers is knowing exactly when your tank is full when filling up at the petrol station. How do you fill up? On the water? or on a trailer? I fill up on a trailer and have noticed that just by dropping my jockey wheel by 3-4 inches i can get another 5 or so litres in the tank. This kind of situation could through your own fuel consumption figures out, and therefore when you try a calibrate the fuel computer you will be inputing the wrong info, this could give you a negative reading.

I suppose there's a couple of possibilities. Firstly, did you change the right figure to 92l. It's not the size of the tank, but the amount you've used that needs to be changed. Then of course once you refill the fuel tank you need to press the reset button to say that the tank is now full again. If you didn't reset the tank level, then i guess that once it gets to zero fuel left (in it's eyes) it will start to show a negative amount.

Keith