I have on my 147 jtd a problem slightly different from what has been discussed.
The gauge is indicating 2- max 3 lines above empty when the tank is full. it works well, i mean it descends according to the fuel consumption until the orange light comes on. this is usually 8-10 liters. then i fill up the tank, and it goes back up to 2-3 lines above empty.
i thought that the floating unit in the tank is faulty, and i removed the fuel pump. i took it out from the tank, i disconnected the sender/floating unit, cleaned it, and put it back. the gauge read correctly, almost full tank. i was happy, and i thought i solved the problem. then, a day after, i started the engine, and as i was driving, in the first 10-15 minutes the gauge was going from almost full, to the same level as before (2-3 lines above empty)
what could be the problem?