Rough Idling...

What is your question?

I have a 95 Dually Turbo Diesel that runs rough when turned on and sitting still. I haven't really noticed any problems while actually driving. It doesn't seem to matter if the truck is in Park, Drive or Reverse, it will idle rough and sound like it is losing power but jumps right back up. It has not stalled or stopped on me, but it sort of feels like it might. I just bought this truck within the last week and this is my first diesel. Any help would be great. Thanks in advance.