Couple of problems with '90 SC

I just picked up a 1990 SC about a month ago, car has 108K on it, the clear coat has pretty much flaked off, but the interior is excellent.
Heres the deal, when driving the car, the max boost I ever see is 5lbs and that drops off quickly as the rpms go up, so at say 1700 rpm I'll hit 5psi and then at 2200 rpm its at 0 and then at 2700 its pulling vaccuum...
The first thing I checked was the boost bypass, figured for sre that would be it, but no luck, it seems to be working ok. About the only other thing I can figure it may be is a boost leak somewhere. Though I can't see anything obvious. Should I just order some teflon gaskets and seal everything up, or any other ideas?

The second thing is when I get on the throttle hard the car feels like its cutting out, I'm kinda leaning towards not enough fuel pressure here, because under light throttle it does ok. What are some major/first things I should look at in the fuel system?

Plugs, wires, clean MAF, oil, air filter, oil filter, fuel filter.

First.

Before you even think of SEARCHING for anything else.

Then let's see how it's running.

RwP

Loose spark plug and bad wires or coil could cause that, Id go with the list of stuff he gave you to do first as just changine the plugs (one was so loose it was a major boost leak) and the wires were shot too, after that she pulled way smoother and harder

Ok, Try free 1st. You can pressurize (engine off) your intake system with shop air. Block off the throttle body & remove & plug the PCV hose. Remove the crossover or any Vacc. line & shoot the air in there. If your leaks are as bad as it sounds you will soon hear a hiss or 2 , so fix one at a time till it is very quiet. Another thing to try is wach how long the Vac/boost gage takes to go to Zero. If it goes quick then you got leaks. Here is an example.

http://www.youtube.com/watch?v=oAauSHbPByE&feature=channel_video_title


If you don't fix the leaks all the new parts wont help.