1997 Plymouth Voyager sometimes the van just turns off whil

Sometimes my van will not start, but the engine turns over just fine. After a couple tries, the van will start. It doesn't seem to be the battery or the starter, because like I said, the engine turns over fine, but it just will not start sometimes. Sometimes when driving the van will just turn off, but will start right back up. I don't have any idea what it could be. Please help