turbo boost 97 9000 aero

I had a 86 900 T with the same problem.

They said that the wiring to the APC box was corroded, or the insulation was bad and there was some shorting, etc.

They fixed it for $27.50 but said I needed $450 worth of more work. Car goes like hell. I can almost spin the wheels in second gear at 8,000 feet elevation.

Go figure.

themodernoman wrote:

Most likely you are tripping to base boost.

Your peddle switches for the brake and/or clutch may have jammed up or your BPC valve has worn through internally. Confirm you have cruise control - if not - check under the drivers dash at the top of the peddle arms. They are sort of a stiletto affair and sometimes don't return to the 'open' position or come off their mounts under the dash.

However, it might also be the BPC - which can be considerably more expensive if let go in that it can short out the APC board. The BPC is that black cylinder on the top right hand side of the radiator with three vac lines coming out.

Without turning on the car, remove the electrical connector and check the resistance on the BPC valve itself (not the loom). There are three pins on the solenoid, using the centre (hot) pin, it should read around 3 ohms to each side (actually to each coil - they share the centre pin as a common power source).

i.e: 3 ohms between #1-2 pins ... 3 ohms between #2-3 pins.

If you are seeing 'infinite' or a substantial resistance difference between the pins - You should replace the BPC unit or disconnect it as there is a fair risk that it will short the APC controller if left in the loom broken. As a consequence, if you have to replace the BPC, it is vitally important to have the APC controller also checked because if the APC has already been shorted - it will blow the new BPC on first run.

I have several posts on the subject over at saabnet.com - start here:

I am trying to publish a fix and am still trying to mooch some dead BPC valves for testing. I can't pay anyone for dead ones, but will be glad to pick up for mailing costs if you want to donate a dead one to the test bench here in Halifax, Nova Scotia.

Flag me through Radio Free Dexterdyne if it turns out your BPC is dead and you feel you can donate it to the project.

Check that the rod on the wastegate actuator hasn't fallen off the turbo. I think on a 9000 it is easier done from under. It should be held inplace by a circlip and an R-pin The R pin goes missing, the circlip corrodes away and actuator rod can fall off.

Then when boost climbs it won't go anyway past atmospheric as the wastegate opens.