Starts but does not stay running?

Hello, I'm Danny.

Are you having the security light flashing on the dash? Here is a security system-anti theft system reset to try first:

https://www.2carpros.com/articles/how-to-reset-a-security-system

The best thing to do is perform a check engine light diagnostic test . Here is a tutorial showing how to perform a check engine light code test:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

After performing this get back to us with any code information and we can the properly diagnose the issue on your car. You might want to perform a fuel pressure test to rule out a weak or failing fuel pump. Here is a tutorial showing how to test fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

The fuel pressure specification on your Astro van is 60-66 PSI with the key on-engine off. Hope this helps and thanks for using 2CarPros.