Hello I have a discovery td5 2003 2.5 turbo diesel any suggestion when my fuel gauge reads a 1/4 of a tank my landrover dies like it ran out of fuel put 30 pound worth of diesel in runs fine I have done nearly 400 miles since it conked out on a 1/4 tank last time replaced the sender unit but still have the issue of conking out when reads 1/4 of a tank any suggestions would be much appreciated for what I can do next thanku