have to crank engine over quiet a few times before it starts. Wondering why?

I have to crank my engine over more than just a few times before it starts. No one seems to be able to figure it out. It always eventually starts but have moments where i get really worried. The last thing I heard was "fuel pressure regulator" from mechanic but now mechanic is not sure of that and cant get part anyway. When it doesnt start at first while cranking i usually stop then try again 30 secnds later. When I do stop however I smell a foul gas smell. I'm glad it still will start but wonder if its going to crap out soon.
Its a Ford Explorer Eddie Bower with 8 cylinder.