Hi Peter,
I can only come up with what Mike has already mentioned.... My low pressure pump (lift pump to the swirl pot), and the Bosch high pressure pumps make a lot higher pitched, louder noise when they are run dry. It's also really bad for the pump to run them this way....
Mine ran like that for about 3 seconds while I was priming them for the engine dyno, so hopefully no long term damage done!
Have you been down to the Sanctuary Cove breakfast yet? The Cobra Club has a breakfast on the first sunday of each month. It's well worth dropping in there to meet everyone.
This weekend is a huge motorsport weekend down at Murwillumbah.
http://www.speedontweed.com Might see you down there!