Ignition problems 400i 1983 | FerrariChat

Ignition problems 400i 1983

Discussion in '365 GT4 2+2/400/412' started by moserpe, Apr 21, 2016.

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  1. moserpe

    moserpe Karting

    Jul 20, 2006
    137
    Switzerland
    Full Name:
    Peter Moser
    #1 moserpe, Apr 21, 2016
    The cold engine starts without any problems and has so far never given trouble while driving. However when switched off, after a drive (hot engine) it is not possible to re-start it. In fact, the ignition does not produce sparks. After cooling down to ambient, it does start flawlessly again. I do conclude that either the Dinoplex electronic ignition or the ignition coil must be defective.
    Before replacing components, I would be interested if anyone has experienced the same problem and whether the reason is to be found in the Dinoplex or in the coil.

    Peter
     
  2. Il Tifoso

    Il Tifoso Formula 3
    Owner Silver Subscribed

    Oct 22, 2013
    1,551
    SF Bay Area, CA
    Full Name:
    Ruben
    #2 Il Tifoso, Apr 21, 2016
    I've experienced this same problem with another non-Ferrari car and it turned out to be the coils, so that would be my bet based on your description.

    The plus side: coils are cheaper than the Dinoplex unit! ;)

    Hopefully someone that has experienced similar symptoms in our cars can confirm/deny my hunch.

    Best of luck!

    Ruben
     
  3. Ak Jim

    Ak Jim F1 Veteran
    Owner Rossa Subscribed

    Dec 23, 2007
    8,500
    North Pole AK
    #3 Ak Jim, Apr 21, 2016
    Last edited: Apr 21, 2016
    Does your car have the single or dual distributors? Also does the single distributor have two coils and two dinoplexes? If it has two of everything I would think the chance of both of them going bad at the same time would be very low. If one of the two systems failed I would think the engine would still start but not run very well. Also, finally what do you mean by the engine does not start? Does the starter motor engage and make the engine spin or does the starter not make the engine spin?
     
  4. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    34,138
    Austin TX
    Full Name:
    Brian Crall
    #4 Rifledriver, Apr 21, 2016
    400i has a single distributor and single ignition box.




    You problem could also be the mag pickup on the distributor.

    If you are sure this is ignition and not a fuel issue I would be most suspicious of the mag pick up and the coil.
     
  5. Ak Jim

    Ak Jim F1 Veteran
    Owner Rossa Subscribed

    Dec 23, 2007
    8,500
    North Pole AK
    #5 Ak Jim, Apr 22, 2016
    Interesting, I'm surprised there is enough dwell time on a single coil running 12 cylinders, I had just assumed there were two.
     
  6. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    34,138
    Austin TX
    Full Name:
    Brian Crall
    #6 Rifledriver, Apr 22, 2016
    There have been a number of 12's with single coils. It was a long time before anyone wanted to go to the trouble of making a dedicated 12 cylinder ignition system so most used 2 6 cylinder systems.
     
  7. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,610
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    #7 SouthJersey400i, Apr 24, 2016
    My vote is for coil if truely no spark when hot.
    Ken
     
  8. alhbln

    alhbln Formula 3
    Consultant Owner

    Mar 4, 2008
    1,749
    Berlin, Germany
    Full Name:
    Adrian
    #8 alhbln, Apr 25, 2016
    First check the VR sensor with a scope, there is a good chance that this one is the culprit. Here is the external wiring diagram:
    http://www.dinoplex.org/PDF/Dinoplex_AEC_104B660-780_Wiring_Diagram.pdf


    Next, remove the two modules on top of the AEC104B and clean the contacts with contact cleaner (not WD40, but industrial contact cleaner who removes the oxidation).
    Also clean the 6 terminal TYCO connector going to the AEC104 while you're at it.

    If this did not fix the problem, try a replacement coil. If you still don't get a spark, the defect is probably in either the trigger circuit or the inverter transformator. If it's the transformater then you would still see tacho pulses on the output connector when trying to start the engine/creating VR sensor impulses.

    Good luck,
    Adrian
     
  9. alhbln

    alhbln Formula 3
    Consultant Owner

    Mar 4, 2008
    1,749
    Berlin, Germany
    Full Name:
    Adrian
    #9 alhbln, Apr 25, 2016
    Last edited: Apr 25, 2016
    This is a capacitive ignition setup, there is no dwell so no issue running 12 cylinders with a single coil.
     
  10. Stefan Elshout

    Stefan Elshout Karting

    Dec 1, 2011
    166
    Holland
    #10 Stefan Elshout, May 2, 2016
    Just in case, this could be an easy way to check if one of your VR-sensors are malfunctioning.
    If you live in Swiss, and your 400i is a swiss version you have 2 VR-sensors (inside your distributor). 1 is a couple degrees retarded compared to the other depending on your throttle position. There is a microswitch on your linkage system that operates 1 VR-sensor at idle and the other one off-idle. So if you apply a bit of throttle when cranking the engine over it should run on the other VR sensor.
    If your car is not a swiss version ignore this post.
     

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