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Flame trap vacuum line routing 850 1994

posted by  chrispalmer on  Sat Oct 16 05:37 CST 2010
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last visit: Sun Feb 16 13:38 CST 2014
[RELATED]

Hi all---I have the problem of excesss crankcase pressure on my 1994 850 turbo(as evidenced by the dipstick test). I purchased a new flame trap kit from FCP Groton and I am in the process of installing it. A similar kit was installed earlier, evidently. The there are two connections near the turbo inlet, one for a large line and one for a smaller line. The setup as currently installed has the large line connected to the oil separator box. A second line runs from the connection at the turbo inlet through a metal tube bolted to the top of the engine and then to a vacuum tree on the intake manifold. A third vacuum line that is in the same insulated housing as the large line is not connected at either end.

What is the correct routing? Is the current installation correct? Should the second smaller line in the insulated housing in the new kit be connected to something on my system? Is it a replacement for the current/original routing through the metal tubing on top of the engine?

I realize that the flame trap system has been discussed in length on this board, so if someone could point me to a previous discussion with an answer that would be great.








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    posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

    Before you attach the large vacuum line to the top of the PTC, clean the PTC out. I know, it is a pain in the butt but that is the next most likely place for a vacuum blockage.

    I cleaned mine just this week, again, and this time I took off the air tube and really gave it a good cleaning. Small screwdriver, TB cleaner, and WD40 on the outside to cleane the old oil off.

    As to the routing of the vacuum lines, there are 3 pickups on the intake air tube, one on top of the PTC(large), one on the side of the PTC(smaller), and one off to the driver's side(small). All three must be connected!

    The large one goes to the oil separator box. The middle one goes to the intake manifold on the passenger side. The stand alone one goes to the EVAP system, if I remember correctly, or to the vacuum tree in 1994. Each year the lines are routed differently.

    Klaus
    --
    Always willing to listen, just not able to take direction.



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      posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

      Thanks, Klaus. I will remove and clean the PTC as well as possible. Thanks also for the guidance on the vacuum lines. I've got the intake manifold out of the car now, but don't see any connections on the passenger side. I will inspect that carefully again when I get home. Cheers.



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        posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

        Just to the left of the #1 intake runner, the port points to the timing belt, as you look at the manifold from the front of the car. It is a bear to clamp up correctly.

        The top of the PTC is round and then becomes square about 2mm down. Be careful with a small bladed screwdriver.

        Klaus
        --
        Always willing to listen, just not able to take direction.



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          posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

          The vacuum connection on the manifold by the #1 intake and pointing toward the timing belt does not exist on my car. I have the vacuum manifold out and can inspect it carefully.

          The vacuum diagram for my model (I think) is here:

          http://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=12325&p=98764

          and I think it shows that the smaller vacuum line from the PTC runs along the top of the engine and then to the vacuum tree on the manifold. It looks like this may be the design for early 1994 models only.

          Cheers.



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            posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

            The manifold line is there for 1995+ engines. I was not even aware that 1994 had a turbo. Interesting...

            Klaus
            --
            Always willing to listen, just not able to take direction.



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    posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

    I'm in the NA boat so I can't help you, though I do believe the 850's have a sticker on the passenger inside corner area of the hood with a diagram.
    --
    If you're not driving it "like its stolen," are you really driving?



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      posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

      The underneath of my hood is covered with a very well attached sound insulation system which makes it difficult to find the vacuum diagram. I'll take a look where you suggest.



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        posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

        it shouldn't be covered by the insulation. It should be on the metal part that goes over the cabin filter area... If its there.. I don't remember what year they started putting it on (my 96 has it).
        --
        If you're not driving it "like its stolen," are you really driving?



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          posted by  someone claiming to be on  Wed Dec 31 18:00 CST 1969 [RELATED]

          Yeah, for whatever reason the diagram is not on my hood. But I did find a diagram on the web that seems to match my car. I post a link below for anyone else that might have the same problems I've had. I have pretty much come to the conclusion after a lot of reading around on various forums that the early 1994 models like mine have a different vacuum routing than the later models, and that the second smaller line in the insulated housing is not used on my model.

          http://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=12325&p=98764

          Thanks again.



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