Just have a quick question, and would appreciate any help anyone could offer. I have a 1999 Pontiac Grand Prix GTP 3.8L SC. Recently, I noticed at WOT it was only registering about 1/2 boost in the DIC. A few months ago it was reading full boost. Anyone have any ideas what is causing this? Thanks!
Only 1/2 boost on gauge
- Thread starter sp33d3r
- Start date
Austins01GP
New member
Vacuum leak. Check your lines running outta your LIM. Any cracks or even pin sized holes could cause this.
That's what I thought it was too, and thank you for the reply. I researched it a little more over the net, and found out it is a bad BBV silenoid. All I did is remove the vacuum line from BBV to the BBV silenoid and fixed the problem. Forgot how good the car ran before that mess-up.
Austins01GP
New member
Well that's good.. And I would bet LOL
01gpgt01
New member
A pin hole vacuum leak will not cause this. It would take a MONSTER leak. I mean to the point of unstable idle to loose boost.
Austins01GP
New member
Yeah your right no way a tiny hole would cause that much loss of boost