A,
Does the pump manufacturer have a technical support line? Call them and walk them through the entire process of what's the problem, what you have done and what results [or lack thereof] you've obtained.
Not sure if the plumping /wiring btw your prior pump and this one is totally different, but if the old pump still works/worked, you could re-install it and see what happens. If you get the same results, then you can safely assume it might be an air-leak you have not discovered. If your older pump cranks-up fine as should, then you know your PVC lines are good and it's prob the pump. Have you made sure that all the settings on the pump are in the correct position?
Finally, what's the return policy of this pump? I would call manufacturer and see if they have not only a tech support line, but someone that they can send out there if you cannot troubleshoot over phone...there's really good people on this board and most problems are identified and solved...
Pls keep us posted and good luck A, tstex