GMC Safari Intermitting starting problem

Here is the situation, 60,000 miles on our van. 4.3 Liter that has
been fine until now.
Condition: no start sometimes, usually in the morning, and after a no
start, it will not start for a few days. Then it starts and run fine,
with no error codes.

Parts replaced, Wires, Plugs, Rotor and Cap, Fuel Filter and Crank
Position Sensor. I started in yesterday, let it run for 30 minutes and
no errors codes.

This is not a dependable transportation for my wife and little ones to
ride around in as we live in the country. Any help would be
appreciated.