Rough Idle & EGR Valve connected?

[luvmy84300sd]

Hi All,
My 84 300SD is doing a lot of "rocking and shaking" at idle to the point that I and my passengers are visably moving while at a stop.....HOW EMBARASING! Here is my situation: I have removed the line to the EGR valve to solve an earlier problem of lack of power at stop and lots of smoke (it worked by the way). I plugged the line and am wondering if the EGR valve itself is stuck in a certain position is this causing this extremely rough idle? It is rougher when the A/C is on, of course, but the car cruises perfectly now at any speed....it's when you come to a complete stop that is the issue.

Thanks in advance for your help!