96 850 Turbo automatic 145k miles

I just picked this car up, and I'm not quite sure what kind of power I should be expecting.

A little background first. The car is in need of a PCV service, the parts will be here tomorrow. There is no CEL on, but I have not scanned for any either. Supposedly the previous owner rebuilt the turbo.

The gauge sits in the black until I punch it, and it will gradually go about a 1/4" into the white. I'm not sure if the gauge is faulty or I have something limiting the boost. I will be purchasing a real boost gauge soon.

I also don't know what kind of power to expect from this car since its my first 850. When I accelerate from a stop, it is a very gradual start, not even possible to spin the tires. Is this normal with an automatic turbo 850? It seems to pull pretty decent at highway speeds but still the gauge will only read about 1/4" into the white.

I tried to disconnect the waste gate acuator vacuume line and I was expecting the boost to increase dramatically, but nothing changed at all, its still the same. I am wondering if the diaphragm in the wastegate is bad.

Ant help would be greatly appreciated, thanks.

 

Whiteblock is soft off the line, mid and top end is where the engine shines. 10psi is what a stock 850 turbo should be doing at max boost.

 

I would get a gauge to hook into somewhere between the turbo outlet and the intake manifold to rule out an onboard gauge problem.( Sorry, couldn`t tell you where)
Like tryingbe stated, there should be 10 PSI max. Otherwise, there could be a problem with the wastegate or there`s a leak somewhere between the turbo outlet and the intake manifold. Accessing all these areas to find a possible leak can be quite difficult unless you have access to a lift. If you have a shop vac with a discharge fitting that the hose will connect, this is a good source of high volume, low pressure air to look for a leak with a spray bottle of soapy water. Just make sure the vac hose is not full of debris that could enter the system.
If you don`t know what 10 psi feels like (I don`t) than you may just have a gauge problem with normal boost. One time a guy let me try out his turbo VW Golf where you could dial in up to 20 pounds. He said it was maxed out, and when I put my foot into it at around 45 MPH, the front tires just broke loose and I had to let off. The gauge on the left A pillar just had colored arcs, but I couldn't really tell what it was doing, trying to keep it straight.

 

Both previous comments are good advice. The factory boost for your turbo will be 9.6psi. The dash gauge is not very accurate so going to about the middle of the white area, to me, would be around 5-6psi. First and easiest thing to do is to pull your ECU out, count to 15 and reinsert it. This will reset it if you are running in limp mode. I do not think you are because you disconnected the wastegate which should have done as you expected. Second thing to do is to look for a leak. This is probably what is going on. to do a leak test does take some fabricating of a block plate and pressure plate but before you go there I would pull off the hose that connects to the throttle body, look under it where the idle control air hose connects to it. This is the most common place for it to tear and is easily missed. If nothing there then you will need to physically inspect all the other hoses and possibly move to making the parts to pressure test it.