Turbo Spikeing?

[g0stx]

My father has a 1995 saab Aero, with 90k miles on it.. He is running the normal(stock) of boost at the moment. I came to visit him and while staying I took out his car a few times, noteing a few odd bumps and sounds from when he first purchased it.. Going down a nice streight and cop-free road, I downshifted into third and planted the go pedal. Turbo spooled up real quick and bam, I was away, but then as the acceleration built up.. *Bam* there was a really odd sensation, like I had just let off the gas really harsh-like and the car lurched for a moment, before contiueing normal operation.. It does this a few more times under high boost pressure, and in most gears and rpm ranges.. Does anyone have a clue what this is? The BOV or the wastegate? Or just too much boost?

He has owned many saab turbos in the past, and none have done this before.....

[SaabJohan]

Try check the solenoid valve (which adjust boost), spark plugs and DI casette.

[saab9kturbo]

those DI cassettes are notorious for wierd failures so get that looked at. it might be spiking and causing the fuel cutoff to kick in, so maybe its time for an HKS blow off valve to make it sound real cool at stoplights, eh? i have a 1987 9000 turbo parts car i got running just for fun and noticed that one injector was running lean and would cut out sometimes and cause misfire under heavy boost/rpm, so if youre turbo manifold is glowing a deep red you might consider that too. could be that solenoid too. did i just cover most of the stuff in the other post? dernit im redunant. oh yea--just make a cursory inspection of all wires and hoses, especially vaccuum, in the turbo vicinity to see if they are ok. like any car it could be a huge number of things to even something silly like the throttle position sensor (not a common failure item in these cars from what ive read and experienced). you should be proud to have a 9000 aero in the family, they are beautiful

[zingZACH]

congrats.... you have just experienced one of the worst things ever.... fuel cutoff lol. happens in my 1990 900T..... i now need to rebuild the engine lol. check the apc solenoid by applying the brake and listen for a click noise... if it DOESNT click, replace it. also, check the wastegate to see if it is locked shut and see what the base boost is set to.