MAKIN'SMOKE

So I'm driving down the road the other day and the truck starts stuttering and the "wait to start" light would flash everytime the truck stuttered it happened infrequently at first and got progressively worse until truck died altogether. when I went to try and restart it the wait to start light would flash on and of rapidly and the FASS would kick in and out maintaining roughly 12 psi (when truck is running normally fp is a steady 16 psi.) but truck would just turn over and not fire. Now for the really weird part after waiting 15 minutes tried to start the truck again and the FASS was not kicking in but the fp gauge was building up to about 6 psi and the wait to start light was still flashing this makes no sense to me because I am running a draw straw with the FASS and the stock lift pump is not even wired in. I checked codes and the only one that was coming up that I had not seen before was 1694. Sorry for the length of this post but I wanted to give as much detail as possible. any help on this would be greatly appreciated as I'm now stuck 900 miles from home without my truck. Thanks inadvance