Date: Wed, 16 Mar 2005 11:06:19 -0500 From: "The Malt Hound" <eric.perduenospaml.com> wrote in message news:1110926071.591128.198760nospam2000cwb.googlegroups.com... >I have been living with an overboost problem on my '92 9000 for a >while > now due to financial constraints. The turbo will boost to where it > starts touching red on the gauge which will in turn cut out the fuel > pump to save the motor...the overall effect is kind of a "bucking" > phenomenon. Very annoying, especially on the freeway, and > potentially > dangerous as power may not be there when needed. A good friend and > car > wiz (not much experience with Saab, but very well versed in most > European makes - he works as a lead tech for a VW dealer) suggested > that I replace the APC valve. His suggestion fit in with the reading > I > have done, so I ordered a new one and slapped it in today. Although > the > problem is alleviated quite a bit, it ain't gone. WHere would be the > next place to look? I want my HP back!!! > A few ideas: 1st, do we know for 100% sure that it really is overboosting and not just that the safety switch is sensing an overboost prematurely? If you have a pressure pump (MightyVac, etc.) you could test the switch to make sure it isn't lying. 2nd, if it really is overboosting, can you actuate the wastegate if you hook up to it directly with the same pump? Use the hose that is normally connected to the APC solenoid. How much pressure does it take? Does the pressure hold or does it bleed off? 3rd, triple check the hose-routing to the APC solenoid is correct. If you hose-up the hoses you might be hosed. ;-) -Fred W