Good on ya for the tank job, but if the car only does 85 now, something is still wrong. It should easily do much more than that. As I've said in other posts, if the car doesn't shift at 4800 - 5000 rpm pulling hard all the way when you floor it, you have other issues.

About the whoosh, I had that together with a weird stalling issue which happened like clockwork a few minutes after a cold start. Replacing the lift pump has solved both.

Rgds,
Chris W.
'95 E300D, 282K