ok my stock charger, is making 1-2 psi depending on its mood, i cant seem to find a good working used one for my car, what would need to be done to put a m90 on my car? or what would you guys recomend??.. the car really isnt worth a whole lot so the cheaper way is the better way for this car(busted fender ground fx fallin off, rust and dents.. but the motor still runs good

please put your year and trim level in your signature, as we have no idea what you are working with

Assuming by what you are saying, it sounds like you have a 92-95, but we are not sure. But what it sounds like is you are pulling massive amounts of KR, and the PCM is dumping the boost to knock the KR down. Please put your year and model in the signature area.

ops sorry about that, i have strep throat and not really paying attention, 92 bonniville ssei all power options,

i have a cold air intake on it, and you can bairly hear the charger making noise, digital dash says 312k miles, which if this is correct and by the looks of it its the original charger and its never been touched

Try a couple things. Pull the vacuum line off the top of the BCA (black cylinder on the front of the SC). Does the boost gauge go up? If not, you need a new BCA.

Then pull the vacuum line off the bottom. Take it for a spin and see if you boost stays real low at WOT. If the boost goes up like it should to around 7-10 psi, a couple things are possible. You need a new boost control solenoid, or, you have weird amounts of massing knock and the PCM is commanding the solenoid to dump your boost. You'll need a scantool. See if Autozone has one you can borrow and have a passenger watch the KR (knock retard, you want 0) or if the Boost % goes down from 100.

ok i just went out and tryed that, with the top line pulled it gets 3 psi and creeps to almost 5 psi by 5k rpms, and when the car shifts the boost goes back to 3 and repets the process,
with the bottom one pulled im gettin a solid 7-8 psi but its breaking up bad, dont pull any harder than 4 psi cuz its braking up and sputtering a lil and popping

Something isn't right if both made the boost go up. Really bad spark plugs, bad fuel, something.

I think you could use a mechanic, or maybe a gearhead here can help.

im a turbo guy at heartso i know my way around a car i just dont know much about supercharged cars, so im cabable of working on it, i know it has good gas in it, and i do know it needs plugs and wires, which as soon as im over strep i will be changing them

Superchargers don't lose boost when they go bad. They make noise, and still make boost.

If you have low boost like that, either the BCS or BCA is bad, or the PCM is dumping boost for a good reason. Bad plugs, wires, improper fueling, or KR due to any number of issues including cracked exhaust manifolds are all possibilities.

You cannot swap an M90 on the car without massive amounts of custom fabrication, nor can you use a Gen3 M62 from a 94/95 without alot of work either.

IF you needed a new supercharger, you need one from 91-93 ONLY.