Low Boost Help

[Jeff Strube]

I have 97 Regal GS it is only making 4 PSI with 3 inch Thrasher Pulley it was making 12 PSI with it Before. Not shure what to look at.

 

[JasonGS]

Check to make sure your boost bypass valve is not unplugged, or checked for frayed/broken wires. When that is unplugged, the PCM will only allow ~4 psi.

 

[Bluto]

I would put my money on a slipping belt.

 

[JasonGS]

Belt slip shouldn't reduce boost that much, unless the belt was very loose. But that is a possibility.

I assume you have supporting mods for that small of a pulley?

 

[kellygtp]

belt slipping was kinda what i was thinking.....Bypass valve could be it though...totally forgot about that...but where are you getting you numbers for the 3.0 at 11 psi stock 3.8's are around 7.5 to 8 psi, and a 3.5 or 3.4 is around 11-12 ish