i have a 2000 suburban w/ 79k. it has a 5.3 vortek motor (i think its a 2001). for over a month i been having problems when i try to start it up after its already been running. it seems like after i drive it for a bit and let it sit for 15-20 min, it cranks over 4-5 times, i go thru this about 2-3 times, then i restart it again while pressing the gas peddle and it seems to start very rough idle for a few seconds.. i replaced the plugs, wires, cam shaft sensor, coolant sensor, and even the crank shaft sensor, all things others have identified as the potential problem. i'm into it for $500.00+ so far and its not improved at all. i would really appreciate anyone with similar problems to let me know what i should consider next. thanks!!!

 

Check the fuel pressure regulator , pump , filter.

 

Starter issue I bet. Install a heat sheild if you know the starter is good. I had the same problem with everyone of my Camaros and the sheild fixed it. It's a chevy thing

 

Starter heatshield is not an issue with these newer Vortec powerplants.

First I would replace the "Ignition 1" relay in the underhood fuse block.
If this doesn't resolve the issue then unplug the vacuum hose from fuel pressure regulator and check for fuel dripping out, this would indicate a ruptured diaphram, if this looks good then have the injectors cleaned.

These are some of the most common causes for extended crank times and rough idle.

 

It was the fuel pressure regulator. Thanks!!