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No spark out of new coil

Discussion in 'Early CJ5 and CJ6 Tech' started by nacheswheelin, Jul 18, 2013.

  1. Jul 18, 2013
    nacheswheelin

    nacheswheelin New Member

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    Sep 30, 2012
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    Hello I have been having some issues with my odd fire. It was running fine and then all of a sudden it just wouldn't start (luckily I was at home). I am getting gas, I have voltage through the ballast resistor, through the positive and negative side of the coil and to the distributor. I cleaned the points, put in a "newer set" and tried a different resistor (not to sure on the name it is hooked to the distributor and connected by a wire to the points). The coil is new and there is voltage through it but no spark, the wires are not the problem either. I am buying a new set of points and a resistor tomorrow, anymore advice would be appreciated thanks.
     
  2. Jul 18, 2013
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    The newest part is often the most suspect in my mind. Substitute a "known good" coil, see it you get spark with your existing system.
     
  3. Jul 18, 2013
    jaysplace

    jaysplace Member

    North, South...
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    Jul 1, 2013
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    80
    The little round canister hooked to the points is the condenser and it can shut you down. I had a 67 Dodge that I shut off on the job and when I came out nothing, just that fast.
     
  4. Jul 18, 2013
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    You realize that the coil is polar? The primary terminals are marked (+) and (-).
     
  5. Jul 18, 2013
    nacheswheelin

    nacheswheelin New Member

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    I hope that that is the problem I don't really see what else it could be, it has me worried though because I tried a condenser that I had laying here and I am sure that it was working. It was off of a 302 so maybe that was why it did not work, I would have bought the parts yesterday but I live so far out of town that I couldn't just run to the store.

    I would have to exchange the one that I bought because my first thought was that the coil was bad. I have current going through the coil and I heard that if there is current going through the coil from positive to negative then it is a good coil?

    Yes I do, I have the wire that comes off of my ignition running through a ballast resistor and down to the positive side of the coil, there is not a wire hooked up to the starter, I heard it would help starting the jeep but have had no previous trouble. The negative side of the coil has the distributor and tachometer hooked up to it. There is power from the positive side of my coil to the negative side and inside the distributor.
     
  6. Jul 18, 2013
    jaysplace

    jaysplace Member

    North, South...
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    Jul 1, 2013
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    Have you checked for power while spinning the engine over? I have had ign. switches in other vehicles go bad so that when I was cranking there was no power to the ign.
     
  7. Jul 18, 2013
    kamel

    kamel Senior Curmudgeon

    Erlanger, Kentucky
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    Jun 10, 2003
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    891
    there should be only one resistor in the circuit -- that is the one that goes between the ignition switch and the "+" side of the coil.

    When you say you have voltage --- the only way to be sure there is voltage anywhere is with a voltmeter. You can't do this with a test light. You should read 12 volts on the + side of the coil, and either 12 volts or 0 volts on the "-" side, depending on whether the points are closed or not.

    So, with the volt meter reading either 0 or 12 volts on the "-" side of the coil, manually turn the engine over until the meter reads 12 volts or 0 volts -- the opposite of what the state was initially.

    If the voltage on the "-" side of the coil is at 0 volts and does not change with the manual rotation of the engine, then the points are shorted to ground somewhere. That could be the condenser shorted or the points physically shorted. Could be as simple as a bad point gap setting never allowing the points to open.

    If the voltage on the "-" side of the coil is at 12 volts and does not change with the manual rotation of the engine, then the points are not properly grounded. OR the connecting wire between the "-" side of the coil and the distributor points is broken ( could be internal to the insulation, and not apparent to the naked eye. Putting a test wire between the "-" of the coil and the ponts and try the test again.. Could be as simple as a bad point gap setting never allowing the points to close.

    If it does change properly with manual rotation of the engine then I'd suspect the coil or the rotor button/distributor cap.

    Note that when taking voltage measurements one wire of the voltmeter should be connected to ground and the other wire moved to the place at which you want to measure. If you start trying to measure voltage with respect to any other point than ground you may get confusing and contradicting results.

    But, first put the correct parts in the unit; not ones found laying around the workbench.
     
    Last edited: Jul 18, 2013
  8. Jul 18, 2013
    sieg

    sieg Sponsor

    bartonville IL
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    I just put a new coil on my 134f and it had an internal resistor and said on the box don't use a resistor with it

    Sent from my XT907 using Tapatalk 2
     
  9. Jul 18, 2013
    nacheswheelin

    nacheswheelin New Member

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  10. Jul 18, 2013
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    After cleaning points I draw piece of clean paper or a business card between them. it can easily happen that a particle of grit or a smear of oil can remain in them.
     
  11. Jul 18, 2013
    nacheswheelin

    nacheswheelin New Member

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    I will try that before I put the new ones in to see if that was the problem.
     
  12. Jul 20, 2013
    1960willyscj5

    1960willyscj5 Well-Known Member

    Mesa, Arizona
    Joined:
    Nov 27, 2006
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    You might want to get another new set of points and install them.

    Just cause the first set are new, doesn't mean they are any good.

    And then consider a Pertronix unit for your JEEP.
     
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