I have a '81 380SL that will usually start great when cold, but you have to let it idle a bit prior to driving or it will die soon as you put it into gear. If it dies (cold), you have to hold the starter 3-5 seconds before it will start again. When cold, the car will lug a bit if you try to accelerate too much. As it warms up the car begins to miss badly and within a few minutes it will die when you come to a stop. You can immediately restart it and it will run. Funny thing is, it will start and idle when hot and you can rev it up while in Park and think nothing is wrong. Soon as you put it in drive, it misses and lugs and will die repeatedly. I've replaced cap, plugs, rotor and wires and most of the vacuum couplings. The problem started with the cold idle/power issue and progressively worsened and now you cannot drive it at all. Any ideas??