If it starts ok after just a few minutes of not running but won't start if it has been sitting a long time like overnight, replace your fuel pressure regulator. The regulator has a check valve inside that is there to keep the gasoline from draining down out of the fuel rail next to the fuel injectors, to help insure fast starts. The fuel pressure regulator sits on top of the gas tank, on top of the fuel pump assembly. The gas tank has to be dropped to get to it, not a big job at all so long as you wait until the tank is nearly empty before starting the job.
When it leaks, the regulator instead lets all the fuel in the engine drain out and back to the gas tank. The lengthy time to start is how long it is taking the fuel pump to get the fuel back up to the engine from the tank.