This may sound odd, but when I had a cam position sensor failing, I would get the start problem you describe. I couldn't reproduce it each time, it was random. Not long after the problem started, I got a code for one of the cam position sensors. Thinking it was just a different problem, I replaced the cam position sensor. Well, it has never failed to start first try again. That was years ago..

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2001 X5 4.4i Sport
2013 550i Xdrive M Sport
2000 528i E39 (Sold)
Unleashed Air Racing 279 mph Best Average Speed