Rumplestiltzkin in my tank

[c.morewood]

I started today with 600 miles on the odometer and the fuel guage showing half a tank.
I'd got to about 550 on the last tank to the halfway mark... so I was thinking I've never done this before .. Whats made this tank last so long?
I get halfway to work and I notice that the fuel quantity is going up... so 20 miles down the road and I'v almost got 1/4 of a tank.
Now as I don't believe in this little guy in my tank making fuel out of thin air...
I was wondering if anyine else had experienced this? Is it possible a bad earth somewhere? Any ideas? I presume the light, indicating low fuel will stilll activate at the normal 10ish litres left?

[Mandrake]

All that's probably happened is that you turned the key on with the car on a sideways slope causing an inaccurate reading on the fuel gauge. I forget which way around it is but on mine I think leaning to the right gives a lower than correct reading while leaning to the left gives a higher than correct reading.

The fuel gauge reading is heavily filtered and averaged to prevent any fast changes in reading, even if you were to syphon out half the tank (with the engine running) the fuel gauge would take at least 15 minutes to indicate the change, this is done so that cornering doesn't cause the fuel gauge to go all over the place.

The filtering is done on the assumption that while the key is on that the level won't be going up (you shouldn't be filling up with the key on ) but will only be going down, and very slowly at that. When you turn the key off and on the filtering is "reset" to the new level to allow for a sudden change in level from filling up.

Recently I accidentally filled up with the engine off but the key on, (I think it was only in accessory, but I'm not certain that it wasn't fully on) and I noticed after filling up and driving away that the fuel gauge was only showing 3/4. I was about to turn around and go back thinking the pump had cut out too soon but I decided to leave it, gradually over about 20 minutes of driving the fuel gauge crept up from 3/4 to full. That's the filtering and averaging at work...

[c.morewood]

Unfortunately that's not it Simon... The car started off level as normal and the level just rose as I drove.. I've just checked it now and its showing FULL!!!!!
Don't you just love these Xantias?

[c.morewood]

Took the pump out and excercised the float... working normally again.

[Old-Guy]

Took the pump out and excercised the float... working normally again.

Bell, book and candle?

[myglaren]

Bell, book and candle?

That was interesting. I was unfamiliar with that quote and had to look it up.
Read a lot of the referenced material but it has passed me by completely.

I do hope the pun was intentional though

[c.morewood]