So I got tired of the fact that my aeromotive fuel pump and regulator are not designed to hold rail pressure after the engine is turned off. I put a check valve just after my A1000, and replaced the FPR with an Edelbrock unit that specifically says it will hold pressure for at least 20 minutes after key off. Key off it drops to less than 6psi in under 2 seconds. At first I thought it was my cheap Vibrant brand check valve, so I blocked the return line, and the check valve holds pressure just fine. It is definitely the FPR not holding pressure. Does anybody have a suggestion for a good FPR that actually does hold key off pressure? I am using -10 inlet and -6 return lines.

 

Why is engine/key off fuel pressure even relevant? It builds nearly instantly whe the key is turned on, so to me it's a non-issue.
Someone explain otherwise to me...

 

On hot restarts, your fuel has boiled off and the entire rail needs to be refilled in order to repressurize. Also, the factory computer expects rail pressure, so you have to tune in a prime pulse delay if you have no initial pressure. I am also guessing that constantly boiling off the liquid fuel in the rails is not good for your fuel injectors. As for your "nearly" instant fuel pressure, that depends on whether the fuel has completely drained back out of your lines through the pump as it will do with an A1000 if the tank is lower than your rails. This amount and therefore how long it takes to pressurize will change with the level of fuel in the gas tank. This all means that you no longer just jump in the car and expect it to instantly start. You have to let it crank for varying amounts of time before it will fire up.