Very odd ignition problem and spark plug wire resistance values....

Discussion in 'Troubleshooting & Diagnosis' started by 70SSRS350, Jul 8, 2021.

  1. 70SSRS350

    70SSRS350 Veteran Member

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    I ended buying the very same (just in red color), but there is still somethibg wrong...
     
  2. Vettenick

    Vettenick Vettenick

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    It seems that you've eliminated the ignition system. Are you sure the wires are in their correct firing order?
    If that's OK, then have you run a compression check to see if it's a mechanical issue?
    You didn't mention whether or not is was better/worse cold or hot?
     
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  3. 70SSRS350

    70SSRS350 Veteran Member

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    Wires are in correct position, double checked.
    Compression check done and it seems fine..
    Cold or warm seems to not affect.
     

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  4. Vettenick

    Vettenick Vettenick

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    Your firing voltages look OK. No burn time info though. That being said, what makes you think it's ignition?
     
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  5. 8pack

    8pack Veteran Member Lifetime Gold Member

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    ^^^^^^ Time to check fuel……looks like you have spark….

    Fuel filter
    Fuel pressure
    Fuel pump
    Carb settings………..
     
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  6. 70SSRS350

    70SSRS350 Veteran Member

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    At first I tought the problem was ignition, I found very odd ohm resistance values on my plug wires, so I focused on ignition... at this point I think it's something else...
     
  7. 70SSRS350

    70SSRS350 Veteran Member

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    This evening (in Italy) I did another test:
    With engine idling (bad as usual) I disconnected one wire at time on distributor (there was spark on distributor/wire when I disconnect).

    If I disconnected cylinder #2 or #3 or #5 or #8, it makes big difference on engine work.
    BUT
    if I disconnected cylinder #1 or #7 or #4 or #6, it makes very small or NO difference.

    Is not possible that (with new parts) 4 cilinders do not spark at all!

    My intake is an Edelbrock Performer (dual plane) and these cylinders are on the same plenum!
    This make me think about the carb!
     

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  8. Vettenick

    Vettenick Vettenick

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    How do the plugs look compared to the others? It might be an intake air leak. The cylinders that did not make much difference would be a lot lighter than the other 4.
     
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  9. MChamp

    MChamp Veteran Member

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    If you got a timing light, hook it to each plug wire as close to the plug as you can and observe the spark. I'm thinking either the petronix, rotor, or cap is bad..
     
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  10. Vettenick

    Vettenick Vettenick

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    His firing voltage is 8-12 kv for every cylinder. Based on that, how can his primary circuit be bad?
     

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