Are you sure that you primed it before adjusting the setting??
You have to "prime" it before using it, otherwise there will be air in the system and it wont work. The only other thing that I can think of is that where you have attached the "T" piece on the vacuem pipe, there is air getting in there. Try getting a couple if tie wraps and tie wrap the hoses on to the "T" piece
Other than that I am clueless
