My 89 F-150 has a blower that starts to run a few minutes after I shut down a hot engine. It seems to blow air onto the fuel injectors for a short time. I have not discussed this with anyone, but my guess is this cools the injectors and may be to prevent fuel boiling in the fuel rail. I do not know if a 94 has this feature. By the way a 4.9 fuel pressure should be 50 to 60 psi.