Just as the title says, after TONS of reading I could not find the answer, even got a buddy on clupGP running a thread to find the answer and nothing yet.
Little back story- I have had my 98 GTP since November 2011. Since owning it, the boost has never risen above 3.4lbs. So I started throwing parts at it since I was unsure of what the culprit was. As of now it has
NEW
LIM Gaskets
Upper manifold gasket (between SC and LIM)
Throttle body gasket
Injector O rings(Lubed and wiggled in to seat them)
Vacuum Tree O-ring
MAF sensor
TPS
IAC
MAP sensor
Evap solenoid
BBV (from ZZP)
BCS (from dealership)
SC belt
SC Idler (old shredded to include belt hence new SC belt)
Acc. Belt
Cat conv.
U bend delete
Cat back (new pipe and mufflers)
Vacuum hose from TB to BBV to BCS to FPR to Snout to MAP to Tree to EVAP solenoid.
I have sprayed carb cleaner all around this engine to find NO vacuum leaks. I monitor my vacuum with the Torque app and it reads 20-21 at idle, yes I know a mechanical gauge is more reliable (not in budget right now).
So I ran across a thread where a wise person told the questioner to remove the vacuum hose between the BCS and FPR and run the hose JUST from the FPR to the snout and then unplug the BCS(electrical connection). READ post number 16 http://www.grandprixforums.net/booooost-68178.html
So I thought what the hell, why not. I did this and got full boost and so fun to drive now.
This has me wondering though
1. Why does this trick work?
2. What about that NEW BCS? (it's just sitting there now, not bolted to the BBV, the new BBV did not have the tab to bolt it down)
3. Are there any side affects of doing this?
