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55 Cj5 No Spark And Questions

Discussion in 'Early CJ5 and CJ6 Tech' started by potshot, May 7, 2023.

  1. potshot

    potshot New Member

    My 55 CJ5 has been offline for a while while I sorted out driveline and suspension issues. Those have been sorted out and now I'm looking to drive it around the block for some tests.

    When I first parked the Jeep I would go out and start the engine just to make sure everything was cool and that's been working fine. This ignition has had the ballast resistor removed and replaced with an coil with an internal resistor. That also has worked fine. I haven't started it in 6-9 months at least.

    So this week I swapped out some fresh gas, charged the battery and I'm seeing no spark at the plugs.

    I did check the coil with the points open, and on the positive side with the ignition on I get 12v, on the negative side 12v, with the points closed the negative gives me 0.8v I'm pretty sure those are acceptable numbers but would take correction.

    Since they are cheap, I'm going to replace the condenser, points and rotor button, although the last two look really good visually, as does the distributor cap.

    Questions; I'm seeing that the rotor buttons for this model are being labeled 6v, should I be looking for a 12V rotor button? Any suggestions on a part number for that?
    Also, where else should I be looking for a no spark issue?

    As always, any help is appreciated. Thanks.
     
  2. PeteL

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

    Rotor "button?" You mean the rotor, I assume. Six or twelve volt should make no difference, AFAIK.

    If you manually open and shut the points, the HT wire from the coil should throw a hot spark to ground. No spark could be the points having oxidized during the idle period, or a short somewhere, although your voltage readings don't indicate that.
     
  3. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    Pull the coil wire out of the cap, make sure the points are closed, with the ignition is on, hold the coil wire close to the block and open the points with a screwdriver, It should throw a nice blue spark to the block. If not what Pete L. says, your points need to be cleaned. I always use a small file, not sand paper, sand paper leaves sand between the points, and they need to be cleaned with cleaner. Good Luck.
     
  4. PeteL

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

    x2. I always wipe with a clean business card or scrap of paper to finish.

    "Point Files" used to be a thing, but good luck finding one!
     
    dozerjim likes this.
  5. BobH

    BobH Member

    Amazon has them.
     
  6. potshot

    potshot New Member

    Thanks guys. Everything's a mystery until you deal with it the first time lol. I found a pretty good video on YouTube that got me through a bunch of stuff I should already know. I'll run out there and work on this after work today. It'll be nice to hear the thing run again.
     
  7. PeteL

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

    Good. But be careful - there is some really terrible stuff on utoob, even maliciously deliberate wrong advice.

    A Factory Service Manual is your best friend.
     
    Twin2, dozerjim and HellaSlow like this.
  8. TonyM

    TonyM Member 2023 Sponsor 2022 Sponsor

    My points here in Mid-Tenn would always get gunked up if I didn't drive, or at least run, the jeep periodically. Not sure if it is the climate or the quality of the parts themselves, or a combination of both, but it did it on my 3A, M38 and my CJ5 if I let them sit for too long. With my CJ5 - the only Jeep that I still have - I replaced the points with a Pertronix unit (and proper wires) for my 6v system nearly 4 years ago and I've never looked back. Purists my scoff, but with the irregularity of how I use the Jeep it's been great for me. I still have the points, condenser, breaker plate, etc in the glove box just in case the Pertronix goes out on the road or trail. Once you get it sorted out it might be something to explore if you won't be driving regularly...
     
    HellaSlow likes this.
  9. HellaSlow

    HellaSlow Member 2024 Sponsor

    Purists only scoff because they want you to suffer like they do.
    I too swapped out my points with the pertronix ignitor. It was an easy upgrade and makes the jeep run better. I also keep the old points in the toolbox, in case of an EMP :worry::rofl:
     
    fyrmn and vtxtasy like this.
  10. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    We always used a Dollar Bill to clean our points of crud, seems to work, can't say why?
     
    Glenn likes this.
  11. Glenn

    Glenn Kinda grumpy old man Staff Member

    Maybe crud is different nowadays? :)
     
    vtxtasy likes this.
  12. PeteL

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

    Probably not, but I'm told points are no longer solid tungsten.
     
    Glenn likes this.
  13. potshot

    potshot New Member

    It was the coil. That and a carb clean and she runs like a top.
     
    TonyM, dozerjim and Andrew Theros like this.
  14. PeteL

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


    (y)
     
  15. Cj5dale

    Cj5dale Member 2023 Sponsor 2022 Sponsor

    What bill should be used in today’s dollars ? :shrug:
     
  16. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    A Big one, Lol
     
    dozerjim likes this.