1994 Lincoln Mark VIII Stalls

When driven to warm up temp, the car starts running ruff, if you shut it off or when it stalls it won't restart, it cranks forever but won't run. When this happens, thier is a strong sour gas smell, not rotten eggs, I've changed the fuel pump & still having the same problem, the filter was replaced this year. It doesn't throw a code to set off the check engine light & I don't have a OBDI reader.Thanks LEE