2001 Dakota 3.9L Dies Reapeatedly

My dad has a 2001 Dodge Dakota extended cab with a 3.9L v6 (standard transmission). It will start and run for a while and it will die, if you turn the key it will start up again but will eventually die. He has changed the spark plugs & wires, the distributor cap & rotor, the MAP sensor, and the throttle valve sensor. It still does the same thing. Any Ideas??

Find a mechanic that will troubleshoot it and figure out the problem, and not throw parts at it?

I know it doesn’t help you fix it, but it’s a good suggestion.