1993 Mercedes Benz 190e Wont start after purging fuel syste

About 1/2 gal of water was accidently put in in the gas tank. Naturally, after a short drive the engine quit. I proceeded to drain the tank by removing a hose at the `fuel pump. Then I purged the pump/filter assembly. Last I unhooked a gas line at the injectors and the cranked the engine a few times til I saw what I thought was a steady flow of gas squirting out. I hooked everything back up, cranked it a few minutes until it fired & ran smoothly for about 20 seconds and died. During subsequent attempts, it tried to start but nada until I got the ether out. Then it would run for 5 seconds and die completely like someone turned the key off. It sounds like its not getting gas. Is there some trick on this car to prime the fuel system & eliminate air in the lines? Any help would be greatly appreciated.