This may not be a fuel pump issue. Leaky fuel injectors will cause pressure to bleed off and lengthen crank times. You can check for sooty spark plugs. Low pressure fuel pump should be making 5 bar ~75 psi not 101. LP fuel sensor may be bad or failing. ISTA has a test plan for this but requires you to install fuel pressure gage to check LP sensor calibration. For HPFP, 5MPa=50bar and this is acceptable at idle. Check at WOT. My N54 HP fuel pump makes ~160 bar at WOT.

Thanks for that info. I ran my scanner on it last night and found the "Smoothness" values in the live data. I don't know what I'm looking for there, all 6 cylinders seemed to create about the same patterns or values, depending on how I had it displaying. I can only see 2 at a time, so I wasn't able to compare all 6, side by side in real time.

I also checked for codes and it's not showing any, so I'm a little stumped at the moment.

Finally got codes registering. P0305 and P0306, misfiring on cylinders 5 and 6. I suppose the thing to do now is swap the 5 and 6 coils to 1,2,3, or 4, and see if it moves with them, right?

That's the usual method to figure out if the coil or injector is the issue.