fix starting problem on my 1989 300e mercedes?

my old merc takes 5 or 6 times to start and only fires after tickling accelerator, it then idles very slowly and unevenly until it gets warm , once it is hot it runs much better but not perfect , strangely the bulb out warning light on the dash came on at the same time asthis problem arose though bulbs seem ok ...... have since replaced plugs ,h.t leads ,distributor cap , rotor arm , fuel filter and fuel tempreture sensor, to no avail ..please can you help