Yeah, you still have two ways from that, well, one...
For air:
Hooked = no vac leak
unhooked = air source
For gas
Hooked @ idle = -10psi pulling press down
unhooked = acts like wot, add 10psi to fuel press
Check fuel press to see what happened.
A doa pressure reg usually you find a dead seal, so you either get not enough pressure, ever, and/or gas in vac line.
It really seems like you have a iac prob.
Unhooked rdm vac **** usually means a high idle. it does run, sometimes, you got s-s-b-b. It really seems like it runs, but don't idle, that leads only to the 'what idles' catagory.