truck will start then stall

here it is long story. I put my truck on its side in a ditch(drivers)6-10 inches of water in the truck..when climbing out the drivers side I stepped in the key breaking it in the column..put in a new lockkey cylinder they coded new to my spare and also cut me a new key using my vin#. Now when I try to start the truck it will fire up then shut down just as fast as it starts. PLease help
its a 99 1500 z71 thanks