Fiesta 1.4 Duratec 04 Digital Fuel Gauge Problems

[Fiesta Drive]

Hi Guys,

I have recently had problems with my digital fuel gauge its not reading the level in the fuel tank correctly its reading full when I know its not and then it may show half full or empty the next time i'd start it. I thought it might be something that would need recalibrating or possibly changing the fuel sender. Now I've started having problems filling the car with fuel (the petrol fuel pump clicks off, at alot of different petrol stations), now I know that it sounds like its a full tank and problems with the fuel gauge, I may have lost count of how much fuel I have put in, but I can assure you that this is not the case I believe there is about 1/4 of a tank in there. Also when I'm driving along the car losses power at around 50 mph and is slow to accelerate around this speed.

Could it possible be anything to do with the air valve on the fuel pump inlet?

Any help or ideas would be much appriciated.

Thanks

Ford Fiesta 1.4 Duratec 04 plate