Max, if the engine idles fine for a few minutes and then dies then you are
having a problem with either the oxygen sensor or one of the temp sensors.
The ECU has a warmup "program loop" that it runs on when you initially start
up the van.  Once it gets a little warm (after a minute or two) then it starts
taking input from the sensors.
Check your grounds first as these can make the sensors go hay-wire without the
sensors actually being bad.
Ken Wilford
Van-Again
John 3:16