late turbo spool problem

[sr24det]

I have a s13 with a blacktop in it. When I bought the car from a guy he said it had a new s13 turbo on it and it does look fairly new. It even has an adjustable waste gate diaphram rod that I have already shortened all the way.

So here is my issue, I have a manual boost controller on it and it should be set around 14lbs. When you get all the way in the throttle, it starts boosting up, but only to like 5lbs and just sits there until reaching 12 or 13lbs at about 5500rpm. This small stock turbo shouldnt have lag like that.
So what is wrong? Another thing i have noticed is that every once in a while when i first crank it up, it will idle like a honda when they have a vaccum leak(up and down up and down) for about 10 seconds and then stop.

cannot find a boost leak ANYWHERE
new walbro 255
new fuel filter
new spark plugs gaped to 30

WHAT IS THE DEAL PLEASE HELP:rant2:

[s14unimog]

A few questions...

How do you know that there isn't a leak? Did you build a pressure system tester? Even the best looking charge systems can have leaks around the clamps and connections.

Are you sure its an OEM T25? Does it say "Garrett" on it?

The other concern would be with that actuator. It could be opening premature and spiking in higher RPM. Ideally you could put it on a dyno and check to see whether it opens when it should; it a little difficult to monitor while driving down the road.

Do you have any pictures of your setup, that might help...