Not sure what you imply with perfect?

As for frequency, if the engine is at idle, it will run for a bit, up to 3-5 minutes at times, before misfiring. under load, it is almost immediate.

No black smoke.

I actually removed the valve core from the fuel rail for the second test to ensure there was no restriction, It still held 50 at key-on with a slight drop to 46 and then back to 50 while running at idle and under load.

__________________
David

2017 X5 S-Drive35i
2005 X5 3.0
2004 X5 3.0