84' 400i, engine suddenly stopps | FerrariChat

84' 400i, engine suddenly stopps

Discussion in '365 GT4 2+2/400/412' started by 400silver, Oct 9, 2017.

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  1. 400silver

    400silver Rookie

    Oct 9, 2017
    8
    Switzerland
    Full Name:
    Michael Keunecke
    Hello, Since approximataly 100km the engine suddenly stopps. Prior to this sudden stop it is sometime not running smothly but gives the Impression that there is only ignition on 7 oder 8 Zylinders, or there are also bangs from false ignition. Spark plugs, rotator caps and rotor have been replaced a year ago, I checked all Relais and fuses (which are typically heated up just before melting temperature beacause they are positioned so badly). The wiring from the Dinoplex should be o.k.. Has anybody an idea what might be the reason to this phenominum? Best Regards
     
  2. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    31,629
    MA
    Full Name:
    John
    Can you give us a little more information, please? For example, does it start and run normal after it has been sitting for a while and then stops after 100km or is it like this all the time now and will not start or run normal even after sitting and being fully cooled down?
     
  3. 400silver

    400silver Rookie

    Oct 9, 2017
    8
    Switzerland
    Full Name:
    Michael Keunecke
    Hello thank for your Kind Reply. The engine stopps, sometimes it starts immediatly, sometimes only after 20 seconds. When it stopps it seems to be very sudden, like somebody would disconnect a fuel pump, ignition or comparable. It reminds me a Little when I had Problems with the ignition lock on an other (Italien) car. I think there is no hot / cold effect,although it stopps basically when the engine is hot. No Problems to get it started when ist cold.
     
  4. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    31,629
    MA
    Full Name:
    John
    As a starting point then I would check all of the electrical connections, especially in the fuel circuits, for continuity and good, clean contacts in the fuse and relay box. Since the fuel injection system is two separate systems and two separate sets of fuses and relays I would pay special attention to the parts of the electrics that service both parts of the system from one point. If only one side of the system was malfunctioning because of a relay or fuse problem, the other side would still work and the engine would still run, although obviously nowhere near as strongly on six cylinders as on twelve!

    I am not a mechanic and it is next to impossible to diagnose something like this over the internet but it does seem that your problem might be electrical in nature.

    When the engine shuts down, does the starter turn strongly when you try to restart and do the lights, radio, other electrical accessories appear to work normally? If not, that would be indicative of a system wide electrical problem and I would then check the electrical ground connection for a clean, tight contact.

    Good luck!
     
  5. 400silver

    400silver Rookie

    Oct 9, 2017
    8
    Switzerland
    Full Name:
    Michael Keunecke
    Hello thank you for your hints, General electric is working normally, starter turns without problems. I also assume that there is an electrical Problem and I checked the fuses and Relais also adding some contact spray, although everything looks new. I had some Problems with the DINOPlex ingintion 10 years ago with the same phenomena. Where is the Speed Encoder of this engine? At the distrubutor? If there is no correct Signal normally it may alos lead to sudden engine shut down.
    TKX
     
  6. Ashman

    Ashman Three Time F1 World Champ
    Owner Silver Subscribed

    Sep 5, 2002
    31,629
    MA
    Full Name:
    John
    Hmmm, sorry I can't help you any further. "Speed encoder" is above my pay grade and I will defer to the experts on here for that!
     
  7. Ferraridoc

    Ferraridoc F1 World Champ
    Owner Silver Subscribed

    Jun 20, 2012
    16,070
    Gold Coast, Aust.
    Full Name:
    Patrick
    It's a magnetic pickup from the distributor, two wires coming out the bottom. Black is pos, red is neg, then it goes to a connector block near the firewall and the black changes to green, the red changes to black. I've just put an MSD on mine and yes, it is confusing.
     
  8. 400silver

    400silver Rookie

    Oct 9, 2017
    8
    Switzerland
    Full Name:
    Michael Keunecke
    Hello , tkx for your help. As I thought the DINOPLEX was the Problem. I replaced it to another(used ) onand the engine never stopped again. Bit it seems, that ignition is less good. BR Michael
     
  9. theunissenguido

    theunissenguido Formula 3
    Owner Silver Subscribed

    Jan 21, 2004
    2,371
    Argent/Brasil
    Full Name:
    Guido
    Its not a good idea to spray Contact Spray at your fuseboard. The plastic layers will desintegrate and make false contacts. If you ever need a new fuseboard with better and bigger contacts, please contact me.

    Guido
     

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