Coachgeo is right, and one project at a time. Be sure ALL your vaccum lines are clear and secure (look for cracking at the splices). Since you think you're having shifting problems also, pay special attention to the line(s) running to the vacum amplifier and from there to the transmission. Then tweak your ALDA (it's not that bad a job once you figure out a good way to deal with the nuts.) If there's no improvement, you're on to deeper and harder things. However, if you can get to a good state after dealing with the integrity of the vaccuum system and the the ALDA you may find your shifting improves. When an automatic transmission is dealing with an engine that isn't behaving as expected at various speeds and rpms it gets confused itself and may shift hard and poorly. In any event, start by keeping it simple. It often is.

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Bart

2002 ML500, 2009 CLK350 Cabriolet
93 300D 2.5 Turbo 265,000 Miles (Sold - bad idea)