88 Bronco 2 fuel system trouble

Hope someone can help. Thing cranks after 2 or 3 attempts and runs fine. Turn it off for about 15 to 20 minutes and it won't crank. Wait hours and it will. No gas to the engine. Have replaced the pumps, filter, pressure regulator and relay. It seems that the gas pressure goes down to nothing after you turn it off. I'm no mechanic, just a regular gal trying to save money by NOT taking it to a mechanic again. Have heard may be a hole in the gas line and that is the only thing we haven't checked but it sounds like looking for a needle in a hay stack. Any and all help will be GREATLY appreciated !