Starts but will not stay running?

The truck lost power and shut off, gave the battery a jump and ran fine the 15 miles to my house. Next day the truck ran well for 30 miles to the next town and started sputtering once I got to the city limits. I had to keep on my brake and press accelerator to keep it from shutting off at traffic light. Pulled into auto parts parking lot and it shut off. Replaced PCV valve and hose because it was damaged, and it started and ran really rough for 3 miles and shut off. Couldn't get it started so it was towed home. Inspecting my truck and troubleshooting I've had to replace the positive battery cable because it arched out on my frame, also my alternator and started had to be replaced due to the faulty battery cable. After part replacements truck started and idle 20 minutes almost like new then sputtering started along with strong gasoline odor then shut off. I replaced the fuel regulator after that and it ran for 3 minutes but very roughly, soon as I pressed gas pedal it shut off. It hasn't started ever since. One thing I did notice when replacing the fuel regulator was that there was a pretty big pile of carbon right in the middle of the manifold.