190E low idle and loss of power

I was wondering if anyone knew what might be wrong with my car... It started having trouble when i was goin up this hill and the car just stopped running. The problem was the the rotor has discinagrated. So i replaced the rotor and distributor cap. Ever since then however my car has been idleing really low and has no power. You have to let the car warm up before you put it into gear or it will stall and to start it most of the time you have to have the accelerator pushed completely. I replaced the coil, plug wires, and plugs to see if it was just bad spark but this did really nothing. I consulted my local Mercedes garage and they told me to try replaceing the cold start valve since i have to let it warm up before it will move...which i have done..but still my car idle's bad and has no power. i have been getting horrible gas milage also... So if anyone could help me in diagnosing the problem it would be appreciated...