Hi. My fuel gauge randomly drops even when the tank is full, then the engine starts to judder like its going to cut out.
mechanic changed fuel sender unit today but its still the same.
any one have any ideas what ot could be?

thanks.

 

my hunch is your fuel pump is intermittantly losing power and that's impacting the sending unit as well. I'm not sure if the pump and sending unit share the same power source so try a quick test - turn the key on and see if the fuel gauge moves. Repeat with the fuel pump relay removed. If your guage doesnt work with the fuel pump relay in place, then it points to a voltage issue and may the relay, pump or wiring. Note that if the problem is solved with a new relay, you may betting an early warning that your pump is drawing too much current (which is what damages the relay) and is about to fail.