1984 Mercedes Benz 190e Fuel supply issues

I've owned car for 6 mos. first couple of months there where no problems,then one day I went to store about a mile away,car started up fine and went to store and shut off car 5 minutes later I went to start and it turns over fine (new battery) and fires at very beginning and stalls out then I go to start car and it turns over fine but doesnt fire up at all,I turned it over for a good 5 min. and it was like a kill switch was turned on,towed car to mechanic after this and my back woods mechanic couldnt figure it out.He said it was getting a spark but no fuel (full tank) if you spray starter fluid it start for a few seconds and stall and not start ,two days later it starts up and goes fine all day then next morning it does same thing again and wont start.Help Please