[bobcowan]

I had a similar problem with a brand new car I built last year. I finally tracked it down to a faulty circuit breaker to the fuel pump. A brand new part, bad out of the box. It happens.

With engine running, start shaking a jiggeling stuff until the problem occurs. I know that sound unscientific, but sometimes it works. Could be something as simple as a loose ground connection, bad relay, or loose fuse.