Could be a multitude of things. If you're convinced it's not the battery then it'll be something either messing up the fuel/air mixture slightly or spark.
I'd expect you to notice any of those things wilst driving though. When is the fuel filter change on an e9x (if it's a schedule item)? I wouldn't be going ripping out the pump unless you're getting other signs too.
First thing to do as always would be check the codes, then do some air/fuel monitoring if you can
Thanks, I wouldn't be doing anything myself, it's under extended warranty.
I read that the issue with the fuel pump being that when the engine is cool and stationary fuel is sucked away from the engine hence the extra cranks until ignition. And that subsequent starts are fine because the fuel in the line hasn't yet traveled back whilst the engine is warm.
Any particular codes or hidden OBD menu I should be looking at?
Could be an earth issue.
Thanks but I think it's unlikely considering what I described above? with subsequent starts being fine.