My Van Was Running OK The nekt day I started the engine, & runs for 5 sec, & stop, keep douing the same thing

Your alarm went off. This is common if it was your crank or cam it would start shut off but give you more than five seconds, Try this roll down a window disconnect the battery and put both terminal together, this will try the BCM(body control module) hod terminal together for 30 seconds reattach the battery put the key in the ignition for 10 seconds in the ACC position then start it. see if that works