checking fuel pressure valve

There is a fuel pressure regulator and a fuel pressure check valve. The check valve is part of the fuel pump, so the pump it self needs to be replaced to replace the check valve. The pressure regulator is part of the fuel rail along with the injectors etc. You check both with a fuel pressure gauge. You test the check valve by letting the car idle and then shutting it off and seeing how fast the fuel pressure bleeds down, it needs to hold at least 10-12 psi for 8 hours or more, other wise there will be a very long crank time to build pressure. Check the fuel regulator and fuel pump by letting the car idle and then removing the vacuum line on the regulator to verify reserve/acceleration pressure.