[stephen low]

I've got a filter in line before the carter pump so wouldn't expect any rubbish to have reached either pump.

I was thinking that there may be something partially blocking the line and restricting flow, would a restriction be likely to increase pump noise?

I was under the car last night and didn't find any items touching metal work etc to give off a resonance type effect ie amplifying noise through contact but I might try a temporary clamp on the various fuel lines whilst I've got the car running to check it out for pipe resonance.

Anyone else got suggestions?

Cheers