Merc running problem

I have a 98 merc marquis with a 4.7? V8. The car ran fine, but sat for a few months and the battery went dead. Put in a new battery, now the car will start and run for 30 or 40 seconds and then quit, it starts right back up and does the same thing. Checked the fuel pressure and it is within the factory limits, where do I go from here?