Couple truck issues

OK,



We have a few Chevy 1 tons that we have deleted for our delivery trucks. They are having a couple of issues and I am wondering if they can be tuning related or having other issues.



First truck:

Will not draw from 2nd fuel tank. Been to dealer thinking it was a simple switch but they have no idea and say that it has to do with the tuning in the truck. Is that possible that option was never reactivated in the new tune?



2nd truck:

Not drawing for 2nd tank just like first truck, also been to the dealer. Another issue they are saying is that truck will rev up to 1100 rpm when put into gear but truck will not move. Driver said he can put truck back in park and then shift again and it will be fine. They said truck doesn't flash any lights on dash and has plenty of power when it moves(not like its in limp mode).



I know its all kinda vague but I am getting the first truck today to get a better idea of what is going on, and then getting the 2nd truck next week when I hopefully get the 1st truck fixed.



Thanks guys