Turbo boost problems

[csbrianp]

I have a 94 850 turbo. I recently replaced the Camshaft sensor, the rear oxygen sensor, but now the car won't accellerate over 4000 RPM without the fuel cut off steping in. I'm getting a over-boost code, but the boost is at stock level. I installed a manual gauge to check and see if the car's gauge was accurate. Lately the car's gauge is showing more boost than the manual, but the kicker happen the other night. I was taking a turn at about 20 mph, I could feel the fuel cut off getting ready to cut, the wastegate was open because I could hear it blowing off boost, and I was hardly pressing on the gas, and the car's gauge registered straight up, not even boosting. Any one have any ideas? If I could figure out how the ECU calculates boost, I'd be able to narrow down my search.

Brian

[csbrianp]

I solved the problem. It was a bad MAF sensor causing the over-boost situation. Oliver at Speed tuning USA, claims that some MAF's have a problem with cold air intakes that I had installed.

Brian

[matthew1]

Good to know -- thanks for the followup Brian.

[Guest]

The problem that I am having with my 94 850 turbo is that the car is jerking at around 3500-4000 rpm. I installed a greddy boost controller and just a cone filter as opposed to the box filter, and the car only jerks when the boost is around 12-13 pounds. Is it my MAF sensor or is it my fuel injectors? And if it is my MAF sensor, do I need to get a new one? If it's my fuel injectors and rails should I get new injectors and bigger fuel rails. Any help on this would be great. Thanks

[matthew1]

Yea, it could be that it's not getting enough fuel. Because with that much boost, you're going to need a similar increase in fuel. That's conjecture because I haven't done boost mods, except for a couple turns on the old wastegate.

[Volvturb]

you might also have a problem with overboost in cold weather, just watch it, it will get better in warmer weather