FI is long gone and dash don't work

J Body General Discussion

  1. BudW

    BudW Moderator Staff Member

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    I can see this going a couple of different ways: One is a defective cluster (or wiring). The other would be powertrain electronics related.

    Is there a computer attached to the air cleaner and is the computer wiring attached to it?
    81 Imperial Underhood.jpg
    It doesn’t have to look identical to this.
    BudW
     
  2. Norse

    Norse Member

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    Darth

    From the (short) long and convoluted history of this car;
    -Possible original owner or second owner tried to live with the FI and instead of having the factory fix it, parked it for about 2 decades (my guess is around 1985-87, probably after the factory guaranty expired).
    -Previous owner twice removed (PO -2) bought the car and tried to fix it by installing an Edelbrock 4-bbl intake and a Holly 750 double pumper. Plus cut out everything electronic that was involved with the factory FI system. Naturally it ran like a turd and he gave up on the project.
    -Previous owner whom I bought it from traded PO -2 for the car, marked the known wiring that had been cut by PO -2 and taped the to the firewall. Then installed an Edelbrock 650 electric choke 4-bbl and a complete Lokar throttle and kick down cable linkage. Plus a Direct Connection electronic distributor and orange box. But due to the fact that he is now 83 and is having a hard time driving (and not really able to sort out the dash issue) sold the Imp plus he's starting to unload his mini junk yard of cars.

    So, now it's up to me to figure out if I can make the factory dash work or to replace it with analog gauges (factory or aftermarket).
     
  3. Norse

    Norse Member

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    BudW

    I'll get a picture up soon but none of what is in your picture is on my car.
    It's now a billet air cleaner on top of an Edelbrock carb.
     
  4. BudW

    BudW Moderator Staff Member

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    The story on post # 22 explains a lot.

    Good news is it is fixable and is most likely caused by the (lack of better term) butchered under-hood wiring harness.
    You even have a few different routes in which to fix the wiring issue.

    In my opinion, I would either find either a "carbureted" Imperial instrument cluster OR a Cordoba/Mirada cluster (non-digital). The cluster was part of the change over from FI to carburetor – so to get it to work, you will need either cluster mentioned above.

    I might recommend finding a good (used) FMJ under-hood wiring harness and adapt it to your car – then swap out the harnesses. Most M & J-bodies are computer controlled (computer that hangs off the air cleaner). Sense your vehicle is no longer computer controlled, you will need to remove some of the wiring (but not a hack job, as before). A person can then (better) tie-in the current electronic ignition system – as well.

    As far as FMJ under-hood harnesses go, there are two main type differences. One has the (square) bulkhead connector on firewall by brake booster.
    Square BH Conn.png
    This is a picture from Aspen500’s fine automobile. Note: it is hard to see the black square on the dark blue.

    The other type has a round boot where the harness goes through the firewall – with a (square) bulkhead connector underneath the dash a short distance later.
    20181207_142527m.jpg
    Note: the black "X" is the starter relay and yellow arrow points to the brake booster.

    Both types have a bolt that attaches/disengages both halves of the bulkhead connector.


    It is best to start off with a harness with same bulkhead connector like you currently have (whichever style it might be). At that point – what I like to do is to get a cheap 4x8 foot sheet of plywood (pegboard or other will also work) and a desk to work on – or make support so wood surface is up/down (like a wall). On the board, take some nails or long screws (screws might work better) at the points where the existing harness branches off and lay your harness on it. Having it this way makes it easier (in my opinion) to re-tape things afterwards – which makes for a much cleaner underhood. Doing this without some support, or on the car, can be a royal pain in the rear.
    Harness repair.png
    The red circles are nails/screws.

    If you send me a PM/conversation, I can show what exactly which wires/connectors will be needed on your harness – once I see some pictures of your underhood and what/which (and location) ignition system you will be using.
    BudW