Please help! I have a 1988 300ce and it is hard to start i pump the gas and it will start but it will only keep running if i keep my foot on the gas as soon as i let up it dies. I replaced the fuel filter Im not sure what to do next.

 

My mercedes ran fine until all of the sudden one day it just died at a stop light and wouldn't restart. It sounded like the engine was not getting fuel supply for some reason. I brought it home and changed the fuel filter. The first few times I started it...it would run for maybe a minute then die again. Today, I went and started it several times with no problem. It is however still running a little rough.
Does anyone have any suggestions or similar incidents that can give me some advice? Thanks!