Read through this post for the ABS.
https://volvoforums.com/forum/volvo-850-16/abs-controller-cover-removal-11104/

If you spray with carb cleaner and there is a leak the idle will either go up or down depending on how big the leak is.

What you did with the Bypass will not test it. The leak would be internal.

Also which turbo is in your car?

 

Well right now to be able to actually drive it decently fast, I took off all boost controllers, although I have to be very cautious on the gas pedal. It seemed to fix it, but I don't think its it.

Ahh, okkay that is understandable. How would I go about go about testing? I'm going to test everything better when i get home.

I believe I have the 15T. 94 Turbo (Non R model or anything) is at Mitsubishi 15T IIRC.

 

You will have to pull the bypass and inspect the diaphram inside.

BTW I have Parts for you!

 

I'll check everything when I get back to WA state.

I just noticed my boost guage is going bad. I'm going to see if that may be the source of the problem. I'm still shifting hard and everything.

And Sorry Tech, I was at an ACT camp. PM me with how we wanna go along with doing this.

 

Does anywhere know where to plug in the side to the turbo for the MBC? I unplugged mine cause I couldn't get my MBC off, but now I can't find it. Where exactly on the turbo? I've tried searching, but every time I can't find it. I'm sure it will be easier for me to do if I knew exactly where it was.

 

Is that little nipple with a nut on it the pressure one I want to install on? To the right of the turbine inlet.

 

Yes plug it to that nipple and then attach the other end to the wastegate nipple.

 

Here is mine (on the 745):

 

Sounds good. Now the hard part, finding it.

 

look from under the car.

 

Better yet just disconnect the lines from the factory controller and put them on the MBC.

 

Everything is back to normal now, except for the vacuum leak. I got the MBC installed again. I had a hard time finding the nipple because the vacuum line broke on it, so I didn't feel it correctly. After a lot of dirt on my hands I got it done.

So are we still stuck on the bypass valve leaking, or could it be something else?

 

Hm, wait, would the BPV really be bad if I could get up to 15PSI without any TCV or MBC?

 

Well, I just checked my bypass valve (that thing was a bitch to get off), but I got it off. I checked the diapram, and everything's fine! What else could be the problem?!






Oh and I had to find out what turbo I had

 

I had some allignment issues and now I need a new set of tires, either 2 or 4 of them. My front passenger outside tread is gone and showing the steel core already. Does anybody have any suggestions on brands of tires, or any tires to get? I'm looking for all season ones, since WA state rains alot.

 

I run Kuhmo tires they are decent in the rain as well.

 

After looking one after your suggestion I have come to a few conclusions.

Kumho Ecsta ASX
Firestone Firehawk GT
Bridgestone G-Force Super Sport A/S

The Kumhos have good reviews, I have some mixed with Firestone and the Bridgestone is fair. The Bridgestone have the best warranty, then firestone, the Kumho. Any suggestions?

 

Like I said I run the Kuhmo's and love them.

 

I have the Bridgestone Potenza RE960AS Pole Position. they are nice.
Kuhmo's are good.

 

I'm running the Kumho Ecsta ASX. I like them but they are not rated that well in rain. Therefore, I do not push them or take chances in the rain, even though I have not noticed any problems in the rain. The Kumho's have a short tread life rating, along with most performance tires. Since I purchased my 850, end of April, I have put over 10,000 miles on it. At this rate, my new Kumho's will not last through the end of the year. I have driven it less than 200 miles in the past month.

I usually get Michelin tires. They have decent grip and a lot longer tread life. The tires I plan to get next also cost about 50% more than the Kumho's though. About $225 per tire vs the $120 per tire I paid for the Kumhos.