1999 Pontiac Grand Prix Supercharger Problems

1999 PONTIAC GRAND PRIX
150,000 MILES • 6 CYL • FWD • AUTOMATIC
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RVENTIGER
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I am having issues with my grand prix GTP when the supercharger boost bypass valve opens. The car runs fine until I step on the gas, and when the supercharge kicks in, the car acts like it is missing really bad. I was able to ty-wrap the bypass valve so it never opens, and it runs ok, but obviously missing power. My main question is, do you think this would be enough troubleshooting to say that it is definitely a problem with the supercharger? Or could it be another problem that the extra boost from the supercharger intensifies? If it's in the supercharger, do you have any idea what it could be? No rattle or squeals. Bad gasket? Any help or extra troubleshooting ideas would be greatly appreciated.

Thanks,
Ryan
Jan 22, 2009 at 2:10 PM
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MASTERTECHTIM
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i would assume that the problem is not the supercharger. i have never seen one fail. most likely the problem is a lack of fuel pressure or ignition breakdown. these super charged engines have a boost for fuel pressure when supercharger is on so the first thing i would do is install a fuel pressure gauge and drive car and see what the pressure does.
Jan 25, 2009 at 6:19 AM