1993 Mercedes Benz 190e cold start problems

I have recently bought a 1993 mercedes 190e 1.8 petrol car, she runs and drives well when warmed up, but has a problem when starting from cold, she will start on the turn of a key no problem, but if you try to accelerate or drive of she missfires and dies, (quite a smell of petrol) the slightest touch of the accelerator will be enuff to kill the engine, however if you gently coax her bit by bit she will after a couple of minutes run normaly and as I said drive realy well, on advise I renewed the plugs distributor cap and rotor arm, but this has not made a bit of difference, when I was replacing the distributor cap I noticed there was oil sitting in the base of the main body of the distributor, would this be a sign that the distributor itself needs replacing or are the problems elsewhere? I dont think this oil should of been there, someone I was speaking to, mentioned a seal must be gone allowing oil to seep up the rotor arm shaft? Please help- advise