Van will not start on 2003 Kia Sedona

Van turns over but will not hold charge (stay running) It acts like it wants to crank but will not. Yes, I do have gas :)Please help me figure this out.

Thank you

Asked by for the 2003 Kia Sedona
If it turns over and wont start check for spark at the plug wires.If it will start and shut off you pro bably have a bad alternator I need to know more info on what it is doing