190E hard to start
 

Just bought a 1989 190E 2.6 .Car runs great after it starts...but have to turn ignition about 10 times before it catches, then runs at very slow and rough idle. After about 3 minutes you can tap the gas and it will rev up and go. Book says not to give it gas until it starts....its right! Give it gas and it doubles the start time. Someone said it needs a new "cold start valve"? Never heard of one.. my 300D doesnt have one....anyway, any suggestions ?