That's the same one I have, ecs brand. The cone adapter works on all of the bmw tanks I have encountered so far. The instructions are good but miss the step to bleed the fill hose after drawing the vacuum, and then draw it again.

I'm not totally sure what you're saying, but I think it would probably cause air bubbles. Which would come out fine in the tank after a couple days of driving.

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'05 E53 3.0 6mt, system too lean bank 1 & 2
'17 F30 340ix 6mt, daily driver
'93 318is, zf5 m52b28 swap