No Spark from Coil - HELP

Discussion in '40- & 55-Series Tech' started by 77TLCFJ40, Jul 2, 2005.

  1. 77TLCFJ40

    77TLCFJ40 SILVER Star

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    Please see attached pictures.

    With key in start or on position, 12v to + & - of coil, but no spark.

    Background: '77 2F FJ40

    Pertronix replaced points & eliminated ignitor

    Tested as good: Battery, Alternator

    Newly installed: Pertronix Module, Starter, Voltage Regulator, Coil (2), Dist Cap & Rotor, Dist Wire

    Thanks for the help.

    Lash
    IMG_0139.JPG IMG_0140.JPG
     
  2. Pin_Head

    Pin_Head

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    With the key on, try momentarily grounding the - side of the coil. It should spark; if not the coil is bad.

    If it sparks, then the coil is good and either the Pertronix distributor trigger or its ignitor (module) is defective or it is wired incorrectly.

    The pictures don't help much as you can't tell what is going where.
     
  3. 77TLCFJ40

    77TLCFJ40 SILVER Star

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    Thanks Pin_Head,

    When we tried that and the jumper wire from the - coil to the - battery got very HOT. This happened on a cheap $10 coil as well as a $30 Accell coil, both NEW.

    We get 12v on both the + and - sides of the coil. Is this correct?

    Here is a little more background on the 77 FJ40

    Drove it 1200 miles to GSMTR and back. It would not restart 50 miles from home after the last fill-up. Diagnosis: bad igniter. I ordered the Pertronix Igniter II and installed it in place of the points and eliminated the OEM igniter two weeks later. It took some trial and error to install, but it fired-up and ran well all 50 miles home. I noticed in the first mile that the alternator was not charging, but made it home anyway. I had the alt tested and it was OK so I replaced the voltage regulator with the Toyota part. After jumping it with another vehicle, it ran and charged very well for a 70 mile round trip ride. The next time I attempted to start, it would not turn over. I had the battery tested and it was OK with a full charge. I had the starter tested and it was bad. The gear teeth were pretty chewed up so I bought a newly rebuilt starter instead of just the solenoid. After installing the starter, still nothing, not even a click. I have also replaced the coil, dist cap, rotor(button), and coil to dist wire. Please remember that the voltage regulator and starter (and maybe cap & rotor) died AFTER the Pertronix install. Maybe they were on their way out the door already?? Maybe I hooked it up wrong and fried my electrical system??

    Here is a wiring summary: Please remember, it ran well this way around 120 miles.

    Pertronix Red wire to + on Coil
    Pertronix Black wire to - on Coil
    Pertronix Module to Dist body ground wire installed
    Black with Yellow stripe (ingition) wire to + on coil
    Black with White stripe wire (through OEM green connector to white wire) to + on coil (formerly connected to OEM igniter)
    NO OEM resistor connected
    No OEM igniter connected

    Another issue at the NEW starter:

    Connected it just as the previous starter (probably original 1977). Only one wire (black and yellow) from harness to engine side of the solenoid. Nothing connected to fender side. It would not turn over at all. Just for ****s and grins, we attached the black with white stripe wire previously used by the oil pressure sending unit (went mechanical gauge) to the fender side of the starter and now it WILL turn over with the key to start. But still not getting spark so engine won't fire. It sounds like the starter issue is a bad ground, but I still have the OEM block to frame ground strap in place and have checked it.

    I'm baffled, but that's not surprising when it comes to electrical systems.

    TIA for all the assistance.

    Lash
     
  4. 77TLCFJ40

    77TLCFJ40 SILVER Star

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    No Spark from Coil - HELP UPDATED More Detail

    Updated with more detail. Please see Post #3. Thanks
     
  5. Pin_Head

    Pin_Head

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    You don't ground the - side of the coil continuously; you just touch it to ground and then remove it. When you break the ground connection it should spark.

    The + and - side whould both indicate 12V only when the ingitor is triggered making a spark; otherwise the coil is charging up and it might read something like 8-12V at the + side and zero at the - side. If you measure the voltage during cranking, you will see that the coil voltage rises and drops as the engine turns. If there is no change, the ingitor and or distributor trigger isn't operating.

    So is the coil good or bad? If it is not the coil, it is probably the ignitor or distributor trigger pickup

    The black wire with white stripe is the ingition start wire and it goes to the solenoid pull in coil lug on the starter. The black wire with yellow strip is the ballast bypass wire and is not needed if you don't have a ballast resistor any more.

    I don't have much experience with Pertronix, but I notice that others have burned them out leaving the ignition key on.
     
  6. 77TLCFJ40

    77TLCFJ40 SILVER Star

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    Pin_Head,

    I will try your suggestion again today.

    I have the Pertronix Igniter II which is designed to not fail if wired wrong or the key is left on - or so I was told.

    Thanks

    Lash
     
  7. Doug_S

    Doug_S

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    It looks like, in the photo, that the wire coming from the Pertronix module isn't hooked to anything. Could just be an optical illusion. Check to make sure that the Pertrronix is wired correctly. I bought at Pertronix I and the d*mned thing didn't fit my non-USA distributor. Be sure you've got the correct one.

    Best regards,
     

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