megan runs fine for miles once i stop and turn it off it is hard to start ?

hi i have a renault megan s reg it runns fine for miles but once i stop and turn it off it is hard to start agin. once it does start it runns eraticaly sounds like its missing or lack of fuel i have taken the fuel lines off the pump engine side all fine plenty of presure and petrol. if i leave it for hours next morning it will start fine and do the same again 5 miles away.help needed please.

ric
April 2009