Intake Problem on 190E
 

I have a 1986 190e 2.3 8v and I got a problem with the throttle body, or at least i think it's the throttle body. When the air filter is off, it is the large valve that is just below the air filter. The problem is, it takes alot of petal push to open that valve. in other words, in order for me to get any power out of my engine, I have to floor it. Plus throttle response is crappy. Any idea how I can fix this?
thanks,
Peter V.