It starts hard and takes a few seconds to fire?

I have a 2.5L mx6. It starts hard and takes a few seconds to fire. I believe there was a light humm or buzz when I would first turn the key on but prior to the starter turning. I am wondering if there is a fuel primer and if this is the result of a fuel pressure regulator gone bad. Does the 2.5L mx6 have some sort of fuel primer that engages prior to starting??