Mine has been doing the same thing this weekend, won't start, wait a day, then it works with no explanation. I was able to start it briefly with some engine start into the intake, but now it doesn't work again. Don't worry you're not alone.
I have '01 325, but same basic setup, I've confirmed I have voltage at the pump but no response from the pump itself, so you're one step ahead of me. I plan to get the replacement installed today.