Hard starts when warm but sitting 1/2 hour

My truck starts fine when it is cold and has been sitting all night, and starts fine if it is started shortly after it has been shut off. However, when my truck has been sitting for about an hour after its been running it starts hard. I have to turn it over for a fair amount of time and then it will start.

If anyone has experianced this I need some help.

JJK

This same thing happend to my recently purchased 99 silverado... the problem is the fuel pressure regulator.... the regulator is on the driver's side of the engine near the back, right above the cylinders, i believe it is at the beginning of the fuel rail.... it just looks like a round thing bolted to the engine with a rubber hose attached to it.... supposidly there are little tiny holes in the diaphram that is inside this regulator, and these tiny holes are allowing fuel and/or air to escape when it is not suppost to... but when it sits overnight this fuel evaporates and you are able to start just fine... the regulator costs anywhere from $50-$100.... i dont know what it takes to replace it though.... my assumption is that it would not be too difficult to do yourself... let me know how this turns out....

Pull the vacuum line from the fuel pressure regulator valve, it is located on the fuel rail on the top left side of the engine... If a few drops of gas come out of the hose, the valve is faulty.. Gas is being sucked through the valve into the cylinders, the truck cranks and cranks until the gas clears....

A new one clips right on, easy to change and diagnose yourself.... Let us know...

Yep my bet is the fuel pressure regulator, just changed mine. It's on the fuel rail driver's side, looks like a vacumum diaphram. Pull the vacumum hose off, if gas comes out it is bad. I got a new one for $50 at the auto parts store, took strong fingers and about 10 minutes to change it, the old one left a lot of parts inside the rail, be sure you get them all out before installing the new one. 110% better since I changed it, cheap and easy fix (without the dealer involved that is) :)

Lance