Hi,
The check valve that "I" referred to when I replied earlier, is in the gas tank and sits on top of the fuel pump sump. The only way to access it is to remove the fuel tank or cut a hole in the back seat floorpan to access it through the top. The check valves in the tank and injectors should maintain fuel pressure on the rail for at least an hour after shutting down the engine hot or cold...shouldn't matter. To check if this is happening properly, you would have to buy an expensive fuel pressure gauge. A crude method would be to push in the schrader valve on the rail after an hour(HOT)and observe what comes out and in what quantity. You should be VERY CAREFUL because when you do this, you are creating an EXTREMELY EXPLOSIVE VAPOR CLOUD! Use some rags to "contain" the vapor and don't create a cloud. You should get a rather constant spray of fuel for about 5-10 seconds. It should be fuel and a bit of air...1-2 seconds worth towards the end of the spray. If you get a lot of air then you have experienced what is termed "Vapor Lock", the fuel gets so hot that it vaporizes, in the rail mostly, and increases pressure a bit pushing the fuel back down the fuel line pressurizing every fuel component in its path. This big pocket of air unfortunately is sitting at the injectors and will cause longer crank times to allow the injectors to "inject" this useless air while they wait for the liquid fuel to return. When an extended period of time elapses the engine and fuel will cool, the fuel will condense back to a liquid and a "normal" start will occur. I see you are in Texas, so I would guess this is what you are experiencing.
...Ed
