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328 wire identification help needed

Discussion in 'Technical Q&A' started by REM9, Aug 9, 2014.

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  1. REM9

    REM9 Karting

    Jun 17, 2001
    175
    Finger Lakes NY, USA
    Full Name:
    Russ Moore
    #1 REM9, Aug 9, 2014
    Last edited by a moderator: Sep 7, 2017
    This is a 1987 328 GTS. I am starting to do a belt service and have found a wire connection that is undone. As a side note my Tach has been reading at a 50% level which I know is a documented 328 problem. This connection is viewed from the RR wheel well (with tire & shroud removed) and also can be seen in the RR corner of the engine compartment. The male end has a green feed wire and the female is a black wire.
    I do plan on remaking this connection but wonder if it is in fact the source of the tach issue for the past few years.
    Any input would be appreciated. I will post pictures.
    Thanks
    Russ
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  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,772
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Aug 9, 2014
    It's not related to the tach (mis)operation. That connection is for the O2 sensor (with it unplugged, your 328 is always running in open-loop mode -- rather than running open-loop when cold and closed-loop when warm).
     
  3. REM9

    REM9 Karting

    Jun 17, 2001
    175
    Finger Lakes NY, USA
    Full Name:
    Russ Moore
    #3 REM9, Aug 9, 2014
    Thanks Steve. For all I know it's been unplugged since I bought the car some 11 years ago. I haven't driven it much, usually opting for the TR but hope to in the near future.
    On the tach I'm going to remove it and try cleaning the wound variable resistor I have read about. If that doesn't fix it, then it's off to Palo Alto I suppose. I have confirmed the signal (actually with your guidance years ago).

    Russ
     
  4. miketuason

    miketuason F1 World Champ
    Owner Silver Subscribed

    Feb 24, 2006
    15,806
    Cerritos, CA.
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    Mike
    #4 miketuason, Aug 9, 2014
    +1 what Steve said. On the tach problem, it could be just a defective sensor located on the bell housing.
     
  5. REM9

    REM9 Karting

    Jun 17, 2001
    175
    Finger Lakes NY, USA
    Full Name:
    Russ Moore
    #5 REM9, Aug 9, 2014
    Thanks Mike. I think that was ruled out back when I first tried to jump into this issue. I believe we tested it and got a signal, but it was so long ago I forgot how I did that. Any ideas? Pulling the tach with hands my size is a PITA and I would avoid it if possible, especially if that wasn't the issue.
    As additional background, I do suspect the windings as I had a humidity issue in the storage area. Cured that with a dehumidification system. Much better-wish I did it way back. Holds the humidity down to 45% now.

    Russ
     

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