Fuel Gauge and computer problem

[s2avant]

2004 is with us and so is a new problem for my evergrowing list.

I got in the car tonight to come home from work and the fuel gauge was reading three quarters of a tank. So? I hear you ask. Well, I had the keys in my hand not the ignition!

When I started it the gauge shot down to empty, the fuel light came on and the computer set off bleeping go to tell me it was empty. After 30mins or so driving the fuel gauge had crept up to the top of the red but the computer was still showing the tank as empty.

When I switched off the ignition the gauge climbed back to three quarters.

I went out later to fill it up as I didn't know how much fuel was in it and this time the gauge didn't move off the empty mark (with the ignition on).

On the way home it all sprang back to life and started working properly again. When I pulled up at home, the gauge dropped down to just above the red and stayed there even when I took out the keys.

It would appear there is some kind of lose connection, but I don't know where to start. Any ideas?

Ben

[A6 AVANT]

Not sure of the type of sender unit fitted to your tank but make sure that the wires to it are ok and you don't have a dodgy earth or feed that is shorting out. Damp weather is lovely for ******ing up connections!! Failing that, see if there are any fault codes? Could be a loose connection on dash or a faulty gauge. I have known the floats on the sender units to go faulty and fill up with fuel or even the sender unit itself! If you have a multi plug on the sender unit, get a circuit tester and check for your live(s) and earth. Some senders use two live wires, 1 for empty to half and the other for half to full.
Personally, I would check for the wires on the sender first and then the sender unit.
HTH

Chris