My van won't start and do not know what it could be? on 2006 Chevrolet Uplander

a few weeks ago we were coming home came down a hill and lost power would not start. We tried changing the fuel pump. We changed the fuel pump and there is gas in the van however it is till not starting. I am wondering what other problems it could be?

Asked by for the 2006 Chevrolet Uplander
you need to have ck'd by your mech and don't waste more $