I start the car - a 2001 Ford Focus 4 cyl DOHC. It runs fine for 30 seconds then stops, as if it is no longer getting fuel. I can’t start it again for a couple days then the same thing happens over again. FWIW, I parked the car for 8 months before this happened and only started it once in that time. But it ran fine then and before I parked it. What can this be?
Have your fuel pump pressure tested and your fuel filter replaced by a good independent mechanic. Your Focus should be running in short order as this sounds like a simple fuel starvation problem.