[JohnG]

Assuming that the fuel gauge returns to zero when you switch the ignition off, the probl...

Assuming that the fuel gauge returns to zero when you switch the ignition off, the problem is probably within the sender unit in the fuel tank. I haven't removed a sender unit but apparently it can be removed and refitted from within the luggage compartment - it isn't necessary to remove the tank. Before doing this, it is suggested that 8 litres of fuel be siphoned from the tank assuming it to be full.

JohnG

 

[RobinG]

Try cleaning the contacts

Often old contacts get corroded / oxidised. Quite often the actual point of contact remain fine, but everywhere around gets damaged, so moving the connector can cause a bad / intermittent connection, and I noticed you had changed the fuel pump, so it might be possible that the connector got slightly moveed in the process.