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Location of fuel vapor expansion tank?

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    Location of fuel vapor expansion tank?

    Where is item 1 located from this diagram: https://www.realoem.com/bmw/enUS/sho...diagId=16_0108

    My 1991 ragtop reeks of gas and needs a simplification/overhaul of the fuel vapor system.

    Thanks!
    "If the sky were to fall tomorrow, the tall would die first."

    -Dr. Paul Forrester



    Do I LOOK like I need a psychological evaluation???

    #2
    Behind the plasric panel in the right rear wheel well. The failed line is likely the large diameter one behind the exposed metal cover in the same wheel well.

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      #3
      Originally posted by roguetoaster View Post
      Behind the plasric panel in the right rear wheel well. The failed line is likely the large diameter one behind the exposed metal cover in the same wheel well.
      Excellent information, thanks! Given the cost of the charcoal canister and other components, is it feasible to just route the vent line to a breather under the back bumper and disconnect the vapor system? I'm smog exempt. EDIT: What would you recommend in general for this system?
      "If the sky were to fall tomorrow, the tall would die first."

      -Dr. Paul Forrester



      Do I LOOK like I need a psychological evaluation???

      Comment


        #4
        Yes, you can eliminate everything, just be sure not to cap any venting or you run the risk if pressurizing the tank and getting vapor locking. Typically the hose from the tank to the expansion is the one that clogs as Toaster said. Our endurance race car ran into this and was causing premature fuel starvation at speed. We kept it, but left the hose coming off the frame rail hard line and looped it by the fuse panel (if it's below tank level, you run the risk of syphoning fuel from the tank). An air compressor was enough to dislodge the clog after a few reversals of air pressure.

        Also, don't dismiss a bad fuel pump seal. They are all bad at this age, and cheap/quick fix vs attacking the EVAP.

        Edit: all vents must be higher than the filler neck in order not to syphon fuel from the tank in certain conditions, bumper or leaving the vent steel line on the tank open is a no go.
        Last edited by ForcedFirebird; 02-22-2020, 03:16 PM.
        john@m20guru.com
        Links:
        Transaction feedback: Here, here and here. Thanks :D

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          #5
          Much appreciated. I have a newish vdo fuel pump. Will replace the seal and reevaluate before I get too rambunctious with the vapor system.
          "If the sky were to fall tomorrow, the tall would die first."

          -Dr. Paul Forrester



          Do I LOOK like I need a psychological evaluation???

          Comment

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