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Need help to ID a rogue fuel went that leads to nowhere

Discussion in '308/328' started by Jerry458, Mar 12, 2025.

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  1. Jerry458

    Jerry458 Karting

    Nov 6, 2024
    87
    NYC
    #1 Jerry458, Mar 12, 2025
    Hi guys was just changing my spark plug wires and saw this hose connected to some sort of a plastic check valve and on the other end another piece of hose going to nowhere. I traced the location and on the drivers side fuel tank fill stem there is a tiny nipple where this is attached too but was dangling and not connected to anything. I looked at all the factory illustrations and do not see any call outs on this. can anyone shed light on this for me. photo attached below. Thanks


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  2. miked

    miked Formula Junior

    Feb 7, 2001
    897
    Cincinnati, Ohio
    #2 miked, Mar 15, 2025
    Need more information, year, model and built for which market.
    My first guess is that it is for fuel vapor emissions capture but those systems can vary widely depending on which year and market the car was built for.
     
  3. Jerry458

    Jerry458 Karting

    Nov 6, 2024
    87
    NYC
    #3 Jerry458, Mar 15, 2025
    thanks it is an 84 QV Euro model im just curious if it plugs into something or if i should cap it off. no canister or emissions stuff on this car i suppose it might be missing since the car was in the US for a long time.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Mar 15, 2025
    Last edited: Mar 15, 2025
    That's the problem -- a 1984 in the US at one time would've had a fuel evaporation control system added to it for US importation (and a bunch of other emission stuff). Now it's been molested for a second time ;). You do need some sort of vent to allow air to go into and out of the fuel tank so be careful about "blocking everything off". This "vent" on a stock euro 1984 308QV would be hose #73 here attached to the small nipple on the filler neck (and it would extend down with the open end to below the chassis frame, so if the car goes upside down, no liquid fuel would come out):

    https://www.ferrariparts.co.uk/diagram/ferrari/308-quattrovalvole/009-fuel-pump-and-pipes

    IMO, if you know the added fuel evaporation system and charcoal canister are gone, you should duplicate the stock euro arrangement. Does your filler neck have that small nipple, or did they put a US filler neck (that doesn't have it) on your car?
     
  5. Jerry458

    Jerry458 Karting

    Nov 6, 2024
    87
    NYC
    #5 Jerry458, Mar 16, 2025
    Hi Steve so the filler neck has this tiny nipple on it so it appears to be sized for about a 1/8 ID hose where this random hose and check valve seems to be connected to but nothing on the other end. Something was connected to it at one time as the other end hose is ballooned and dry rot cracked. above that is a larger nipple where the clear PVC hose attaches which seems to be a drain or overflow tube? and runs down along side the drivers fuel tank strap to the bottom of the chassis.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #6 Steve Magnusson, Mar 16, 2025
    That makes sense as that small nipple is a logical place to add a fuel evaporation control system. (The US version 308QV have extra fittings on top of the RH fuel tank for connecting the fuel evaporation control system.)

    That seems rather strange. The euro 308QV SPC link that I posted earlier shows that that larger nipple, with the clearish hose #68, should connect to a pipe system that connects the filler neck to the tops of the two tanks, but is not open to atmosphere. I can only restate that maybe you should try to match the stock euro 308QV configuration as shown in that SPC figure.
     

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