DY3 motor, rubber hose under intake manifold?
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Thread: DY3 motor, rubber hose under intake manifold?

  1. #1
    Tadpole
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    Default DY3 motor, rubber hose under intake manifold?

    Hello all!

    I recently purchased a 1974 DSuper and the forum here has been a wealth of information for an American in Belgium!

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    The carb (Weber 28/36 DLE A2) was running a tick off, so removed it to clean, freshen the gaskets, and flatten the bottom deck with the help of the 814 manual and the forum. The throttle bar guide plate rubber was torn, so it was a good chance to do that as well.

    All was okay except it won't start now, but there's a drip from the bottom of the intake manifold onto the heater pipe. I don't think I knocked something down there off, but reviewing the 648 books shows a hose from the bottom the intake manifold (2-141, part #9). I only have about 1" of hose on the fitting and that's where it dripped out of when trying to start. Where does this hose go to? I don't think it's a fuel vapor drain as I've seen on other vehicles, but stumped and a forum search didn't reveal anything. I hadn't noticed anything out of that hose before.

    Thanks for the assistance and the wealth of knowledge you've already provided!

    Claus

  2. #2
    Fellow Frogger!
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    I've got a DS 21, and it looks to have the same 'four pipe' manifold as the one you are describing (and from what i can see in manual 648). I fitted my manifold to my engine last week but not the carb. Inside the manifold you can see there is a groove to channel any (condensed?) fuel/air down that nozzle. the connected pipe should be 30 maybe 40cm long (length will be in manual 648). It gets brittle and snaps off. Maybe you disturb and broke it when working on the carb? Alternatively, if you've got water dripping under there, it's could be that the core plug right at the back that has rotted through. Mine had, and I've replaced it. (Before and after photos below!) I think it's 30mm. I can check if you need me to.

    UPDATE. Going back to 648 to confirm the length of that drain tube (its 40cm), i notice that the manifold in the picture has the core plug on the front, vertical, face, rather than the bottom. Maybe a design change to delay it rotting out? Anyway, if yours is like that, then i guess it would be pretty obvious if the core plug was the source of your drip.

    Sound to me like your car is flooding so that fuel runs down the carb throat and is vented via the pipe on the manifold? Stuck float in the carb?



    DY3 motor, rubber hose under intake manifold?-img_6006.jpgDY3 motor, rubber hose under intake manifold?-groove-manifold.jpgDY3 motor, rubber hose under intake manifold?-core-plug.jpgDY3 motor, rubber hose under intake manifold?-new-core-plug.jpgDY3 motor, rubber hose under intake manifold?-new-core-plug-2.jpg
    Attached Thumbnails Attached Thumbnails DY3 motor, rubber hose under intake manifold?-img_6008.jpg  
    Last edited by Budge; 14th January 2018 at 01:51 AM.

  3. #3
    Tadpole
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    Thanks for the tips again on so many fronts. I took the top back off the carburetor and surmised the float needle valve must be allowing continuous flow, so re-clean/re-check/re-install and good to go!

    I made a note in my 648 PDF about that freeze plug...mine is on the underside as well. For the tube, I'll get a section to route it. Your manifold and engine look great, I assume you're in the middle of a rebuild?

  4. #4
    1000+ Posts forumnoreason's Avatar
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    Clean the filter which is housed next to the intake nozzle and has a big nut on it.

  5. #5
    Fellow Frogger!
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    Quote Originally Posted by cfasting View Post
    Your manifold and engine look great, I assume you're in the middle of a rebuild?
    Thanks. 'Middle' is a bit generous but I'm getting there... water pump housing and pump going back on this morning. Alsov rebuilding the starter (a Ducellier 6182) and polishing the heat shields. Carb (Weber 28/36 DDE) rebuild kit on order, as are kits for the pressure regulator and front brakes.......
    GreenBlood likes this.

  6. #6
    Fellow Frogger! citroenthusiast's Avatar
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    Typical Citroen. A clever, elegant design. The drip tube allows fuel from a flooded engine to drain, but is designed to be too long for dirt to be pulled into the engine at idle or overrun. If the tube has snapped off short, it will still work as the former, but not as the latter.
    Cheers,
    John T.

    54 TAV Legere; 61DS19 LHM BVH (son's); 71DS21 BVH; 73SM 3.0; 73SM EFI (Megasquirt); 73SM 3.0 (other son's)

  7. #7
    Fellow Frogger!
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    Quote Originally Posted by citroenthusiast View Post
    Typical Citroen. A clever, elegant design. The drip tube allows fuel from a flooded engine to drain, but is designed to be too long for dirt to be pulled into the engine at idle or overrun. If the tube has snapped off short, it will still work as the former, but not as the latter.
    I agree: right idea, but wrong material. Well - wrong material if you expect it to last 50 years What's the best thing to replace it with? I didn't include the photo in my earlier post, but mine snapped right at the nozzle end. I was going to try and source a length of Rilsin.

  8. #8
    Fellow Frogger! citroenthusiast's Avatar
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    A rilsan tube with a short piece of Viton rubber tubing at the junction should outlast all of us....
    forumnoreason likes this.
    Cheers,
    John T.

    54 TAV Legere; 61DS19 LHM BVH (son's); 71DS21 BVH; 73SM 3.0; 73SM EFI (Megasquirt); 73SM 3.0 (other son's)

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