1987 Volkswagen Van My first question in this website.

I have a VW Vanagon Campmovil 1987 ,2.1 liter water cooler , the problem is it stars good and starts to run good for 5 min or less ,and it starts to loose power and the engine dies. I start it again and it runs good for 5 or 6 min and do the same thing, the engine dies.
I already change the spark plug and spark plug wire, the Distributor cap and the rotor ,and fule filte,
I will make a donetion if you helpme fix my problem.
Thanks
Victor. D. Marrero