99' 4.8 hard starts

hey, im new at this so bare with me, I have a 99 with the 4.8 it has about 107,000 miles, and recently ive noticed that when you go to restart it after it has been running for a while, it doesn't like to start back up. if you leave it sit over nite its fine. but say you drive it and let it sit for 30 mins, when you go to restart it, its very rough, it just cranks for about 15 seconds, then decideds to try to start after you give it a little gas. after it starts it runs great. i've been told several things of what it could be, but i dont have the money to replace everything, i just want to know the problem, i think im also seeing a slight decrease in gas mileage too. please help! thanx so much!!!

fuel filter original??? change it if not sure...
if that doesnt help then check fuel pressure regulator, im not sure if its different on 4.8s from 5.3s but on top of the drivers side valve cover, there is a black thing with one vac hose hooked to it, pull that while its running, if you get gas then replace the regulator.

Sweet I'll try this, i hope it does the trick because I've heard way to many things of what it could be. thanx again!

Well I just pulled off the vac hose and i didnt even need to start it. when i pulled it off fuel spewed out. im guessing this is bad? and this "black thing" is on top of the manifold right next to the valve cover. Im assuming thats it. haha. how much do one of these cost and how hard are they to install your self

I got one last week from Advance Auto Parts for about $50. AutoZone wanted like $80+. Advance was by far the cheapest place around for the exact same part. It is only held on by a clamp so just remove the clamp, pull the bad one, stick the new one in (you may need to get some channel locks or vise grips to hold it in snug) and then just stick the clamp back on. Two minutes tops!

thatd be it.....with that many miles, id pick up a new fuel filter while your there.....