I have an 02 jetta 1.8t done the exaust, turbo inlet, cold air intake with k&n, upsolute chip v12, turbosmart adjustable, blow off valve, audi h version n75 valve..but it will not hold stable pressure from 5-23 psi.  could this be fuel delivery???mabe more gpm .....bigger injectors?? fuel pressure regulator???all of the above?i am not sure but can this turbo can create and keep 20-25 psi stable  

On an 02 Jetta you should have an AWP with the sport turbo(however I have stopped being suprised at finding out of place things in VWs) The AWP should be able to hold between 17-20psi and you should spike at about 23-25psi.
More than likely it isn't fuel delivery, your stock fuel system should be good up to about 25psi. You would probably see other symptoms with a fueling problem also.
Your stock turbo doesn't want to hold much more than about 18psi, you can convince the wastegate to do about 20 but you are really on the downside of the turbos efficiency by then.
At this point you are looking at a new turbo. Also, I know this has been debated to death, but you may be better off with a DV instead of the BOV.  

sorry mike....awp??and this set up will stablize around 12-13 psi @ 5500 rpm but seems to be out of pull by then and @6000rpm will blow down to 5 psi and then come back to 12-13psi.....could this turbo just be ready for the extended care unit  

At lower RPMs you should be getting about 18-20psi(around 3500RPM) it should start falling off the closer you get to redline, by 5500 RPM you should be down around 10psi. Your numbers sound a little low to me. It may be a bad turbo but I would first check for boost leaks, bad blow off or wastegate. If you have a VAGCOM you can scan for codes and requested boost vs actual.

If you are really trying to run 20+psi, this would be a great time to do a turbo upgrade.