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84 BB512I no spark problem.

Discussion in 'Technical Q&A' started by tbakowsky, Nov 13, 2003.

  1. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,609
    The Cold North
    Full Name:
    Tom
    I've been fighting with an 84 BB512 with a no spark problem.

    I have sent the digiplex out to be repaired once, and then it was sent out again to make sure it was working....The box is fine.

    The ignition coil is brand new(came with the new ignition box) It was also sent back for checking...it is fine.

    The pick-up on the side of the distributor was swapped out with a pick-up from another BB512...it works just fine.

    I have 1.5Ac volts from the magnetic pick-up on cranking...this is within spec. I have 1.5AC volts at the ignition box at pin 6...this is fine.

    I have power coming in(yellow wire) and stays at a constant 12volts while cranking and when the key is in the run position. This is good.

    I have good ground for the box. checked with meter.

    I have perfect continuity for the ignition coil wire.

    Everything i have checked tells me this car should be running.


    Today just to eliminate the possiablity of bad wireing I made my own harness independent of the exsisting one in the car. I ran fresh brand new wires from the terminals on the ignition box directly to the controled component thus eliminating any chance of a harness problem. Still nothing.

    The car turns over very well (new batt) The ignition rotor is turning (belts are not broken) it has plenty of fuel.

    The ignition wires are brand new. But I'm getting zero response from the ignition coil itself. But the coil tests fine.

    Does anybody have any idea what so ever as to what could be wrong with this car? It there anything inside the BB512i distributor that could be causing this problem(the distributor ground is fine).

    Guys I'm at a total loss with this car. I have never seen anything like this,and I have come accross some wacky stuff. But this car has me stumped.

    Any help would be appreciated!!
     
  2. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,609
    The Cold North
    Full Name:
    Tom
    #2 tbakowsky, Nov 13, 2003
    Last edited by a moderator: Sep 7, 2017
  3. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,299
    Alabama (was Mich.)
    Full Name:
    Jeff
    During my TR service I noticed the carbon button in one dist. cap was nearly gone...almost totally "disolved". Could it be something like that?
     
  4. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,609
    The Cold North
    Full Name:
    Tom
    Nope...I'm getting no action at all from the ignition coil itself. I've even tried ocillating the box with a nine volt battery and still nothing.
     
  5. ferrarioldman

    ferrarioldman Formula 3
    Professional Ferrari Technician Silver Subscribed

    Jun 19, 2002
    1,008
    Summerfield, NC
    Full Name:
    Tom Jones
    When you turn the key on, do you hear a high pitched "whistle" coming from the digiplex ?
     
  6. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,609
    The Cold North
    Full Name:
    Tom
    I have replaced the digiplex with a rebuilt unit from permatune. If you would like to see the box go to http://www.permatune.com. It's the 104B. Basicly this is like an MSD set up except they build everything inside the original box and use the exsisting wireing in the car.

    So to ansewr your questions about the buzzing noise no it does not. But I know excatly what you are refering to.

    I have sent the box,and the coil to be checked by them for a second time and they said it was fine nothing wrong with either one of them.

    I have replaced the box,coil,pick-up and wiring....still nothing how can this be?? How is this possiable. The ground on the distributor is fine,the output from the pick-up is good. With the engine cranking power at the box show 11volts...this is good. I have measured the air gap between the reluctor in the distributor and the pick-up good on all 12 points.

    AAAARRRRGGGG I'm about ready to put this car in front of my shop and plant flowers in it!! (nice pot huh?)
     
  7. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,220
    TN
    What about a chassis to engine ground wire. Can you test it by using a quick ground strap connected to each?
     
  8. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    My guess is the digiplex (it's not whistling would worry me) as far as I can remember all digiplexes whistled - is it not possible to try a digiplex from another car, this would at least eliminate it.

    Are you saying there is no spark at the sparkplugs, if so check the distributer cap with a meter, also check the rotor arm - apart from that you seem to have covered everything else.

    MW
     
  9. thecarreaper

    thecarreaper F1 World Champ
    Silver Subscribed

    Sep 30, 2003
    15,373
    Savannah
    Full Name:
    name
    ok this may be a stupid response but have you ruled out a hidden ignition kill" switch, like an anti theft device???? i saved a car from the junk yard because no one could find the wire and switch that was hidden IN THE FREAKING ENGINE COMPARTMENT NO LESS! it was wrapped in the factory wiring and the switch was under a blind " flange " in the sheet metal. it sounds to me like you have learned alot about yoour car, but the desperation is there too!!! good luck.
     

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