Ok, so I have a 94 850 turbo. The car cuts out when the car shifts from first to second gear (auto trans) From what I can tell on the boost gauge, it sits at about 90% in first gear, then when it changes to second the gauge goes to the end and the car cuts out. From what I've read on here it could be a fuel cut off from a boost spike...? What causes that? Where do I start?

Also the car seems to be getting really bad gas mileage. I do drive short distances, like less than 5 miles to work...I know that can contribute to poor mileage, but this seems excesive. When I first got the car about a month ago the mileage readout said an average of 24 mpg....it now reads 19. Since I bought the car I've done a full tune up including plugs, wires, cap, rotor, and air filter...I have yet to change the fuel filter though. Also the only codes I get are a knock sensor code.

I've also read that I should replace the PCV system, as I have oil under the cover on the top of the engine..looks to be coming from the oil cap. I did pull the dipstick out while the engine is running and see a tiny bit of smoke coming out....It seems this can cause poor fuel mileage...? Not sure how though...pressure inside the block working against the pistons? Sorry for all the questions, I'm a total noon to Volvos and also Turbos haha Go easy

Thanks for any help, Joe

 

Bump No ideas?

 

Dang, no one wants to help out a noob!?