Installation of the new and improved fuel pressure regulator spring will help ensure that the fuel pressure remains above the oh-so-critical 45psi. This 'Blue Spring Upgrade' could prevent damage to your injectors in addition to helping avoid a no-start condition.
Two different versions of this kit are available. The complete kit with cover and the version that doesn't include the unnecessary cover, but also doesn't include a white/black plastic valve that a token few report broken upon inspection.
A great installation write-up can be found here. Many Ford techs have been trained to place a 3/8" or so blue dot on the cover if the spring has been replaced already. If you don't have the dot, you likely don't have the spring.