Hi all,
I have a thread going on my 1996 Volvo 850 turbo and it's starting issue. I have found a missing vac line at the vac tree and when I plug the port with my finger the car will idle without the gas pedal. I think I may have additional vac issues but I am starting with the one I found. It's on the vac tree. Two ports on back facing rear. Top port goes to fuel pressure regulator. Where does the bottom port connect to ? I have attached an image to help. Thank you

 

It doesn't really matter which line is which. What matters is what you're missing.

On a 96 turbo, on manifold vacuum, you'd have the boost gauge, cruise control, and whatever is on the vacuum diagram. You may actually have all you need there. I don't have a 96 handy, but on the internet it looks like they have air injection and that is the white line. They have evap purge of course, but that is the larger line below the tree. Power brakes also don't go to the tree. does your boost gauge work? I can't remember whether it comes off the tree or not.

 

The boost gauge isn't working and it feels like the car isnt boosting. It looks like there was a line there bc the port is clean compared to the rest of tree. And it helps my idle to have the port plugged.

 

on my 95 850T the vacuum tree has two capped stems. I had one blow off - which I suspect was caused by a clogged PCV system. I will go out and look at my 95T in a few minutes to see if I can follow where that lower tube goes and reply back later.

 

Appreciate it. I ended up putting a cap on that lower tree port. I got some video I am going to post.

 

The boost gauge is a hard black plastic line running over toward the battery, if I remember correctly.

 

Not sure if you're still trying to suss this out, but here is the vacuum line routing on my 96 Platinum Edition. Looks like there are only 2 lines going to the tree: the fuel pressure regulator and the boost gauge.

 

On my car the white line is air injection, so I think his car has that too. I have no idea why they'd not be all the same.