fuel related starting problems

Can anyone help with an intermittent starting problem on my disco td5. I have been advised by the AA that they think the fuel pump in the tank is goosed. I have changed the heater plugs, fuel pressure regulator and the fuel filter at a combined cost of almost 300quid, but the problem persists.

There is a noise coming from the fuel tank area which is now constant and can be heard over the sound of the engine.

Any advice would be greatly appreciated,

cheers

Ziffter

could well be your fuel pump but also the whine could be caused by air in the fuel system

Plumb a pressure gauge into the fuel supply,it should maintain 4 bar pressure all the time the pump is running.I have one set up to plug right into the pressure reg at the back of the cyl head with a long hose so I can tape it to the door mirror and watch the pressure while on road test - works a treat.