Intake manifold problem

Hey, W211 E350 '06 with M272 V6 7G, 120k km mileage (74, 5k miles). The lever on the intake manifold has recently broken (swirl flaps), so I bought an aluminum one and replaced it. Before and after replacement while trying to move instead of smoothly take off car goes on 4,000 to 5,000 RPM's, then jerks (just like quick release of clutch). Same happens while driving, doesn't matter on which gear it goes or how fast you driving. Sometimes the replaced lever got stuck in the closed position. The power drop is also noticeable.