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No Spark To The Plugs

Discussion in 'Early CJ5 and CJ6 Tech' started by marty salisbury, Mar 16, 2021.

  1. All, it has been awhile since I last posted. But the COVID Shutdown has given me a lot of time to work on my project. I am in the process of starting it up and ran into an issue with it firing. I read up and have spark at the points with the ignition on, ground the coil wire and open the points with a small screwdriver. I used the timing mark on the crank pulley to align and make sure the rotor is at the 5 o’clock position. I have new points, condenser, rotor and cap on order (the first order was the wrong set up). Any advise as to where to go now?

    I also attached a picture of my project.
     

    Attached Files:

  2. Ohiowrangler

    Ohiowrangler Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Do you have coming out of the coil?
     
  3. If I ground the coil wire i can get spark in the points if I open with a small screw driver. If there is another way to test please let me know?

    marty
     
  4. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Make gap from the coil HT wire to ground (hold the wire 1/4" from the block), and see if you get a spark when you open the points. You can also lay a spark plug on top of the engine, connected by its plug wire. Crank the engine and see if you get a spark across the plug gap.
     
  5. I’m trying to understand, are you saying take the coil wire from the distributor cap hold 1/4 inch from the block an open the points to see if I have spark in between the end of the coil across to the block?
     
  6. jeepdaddy2000

    jeepdaddy2000 Active Member

    Yes.
    Turn the ignition on with the points closed.
    Hold the distributor end of the high tension wire about 1/4 inch from a ground (block). DO NOT ALLOW YOUR FINGER OR OTHER BODY PART TO GET CLOSE TO THE END OF THE WIRE.
    Open the points using your fingernail or other non conducting material. You should get a spark from the wire end to the block every time you cycle the points open and closed.
     
  7. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member


    Sorry I'm not understanding something here about grounding the coil, the coil is grounded by the points closing- the current flow is battery-ignition switch-coil "+" terminal-coil "-" terminal-points-ground (engine block). You're getting spark even though it sounds like you're somehow connecting the coil "-" terminal to the block bypassing the points. Can you elaborate?
     
  8. So I just went out and unplugged the coil from the cap and turned the ignition on. Every time I opened the closed points the spark jumped from the coil wire that was grounded to the block.
     
  9. PeteL

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

    So it's all good as far as the cap and rotor.

    Is there a rotor installed inside the cap? Is the center brush (rotor contact) inside the cap present? Is the cap clean and dry, inside and out?
     
  10. scoutpilot

    scoutpilot Member

    Pull the spark plugs. Examine them for carbon buildup and/or fuel fouling. If either/both, clean, re-gap, re-install.
     
  11. I will look at the cap and rotor later today, I have new plugs and plug wires. I removed the points to replace during the cleaning process but the new points were not correct so I put the old components back in. I am waiting for the correct points, cap, and rotor to change out. The engine ran before I stripped everything and started the rebuild. Thanks to everyone for the information.

    Marty
     
  12. jeepdaddy2000

    jeepdaddy2000 Active Member

    Stupid question:
    During all of this, did you reset the point gap/dwell?
    If there is zero gap when the lobe runs under the rubbing block, the points won't open.
     
    PeteL likes this.
  13. I did rest at .020 at full open and will check again later tonight. The dwell I assume you are talking about the closed position? I think I may be missing something from your last post? Points open and close when I turn the engine.
     
  14. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Dwell is the angle in degrees that the points are closed. It's a function of the clearance between the points contacts (gap) when the fiber block is on the peak of the distributor cam.

    Usually the angle is set to (mostly) evenly divide the coil time between charging (closed) and discharging (open). For a 4-cylinder, there are 4 periods closed and 4 periods open, 360/8 = 45 degrees.
     
  15. Tim,
    Thank you for explaining, I was looking up on line but your information explains it perfectly. I will look at this tonight and see what I messed up when putting it back together. I have to say it has been awhile since it replaced and set points. LOL. Thanks to all for the information to my questions and teaching an old dog new tricks.

    marty
     
  16. Shopteach

    Shopteach New Member

    If you have spark from the coil and new wires and plugs it almost has to be the cap or rotor.
     
    ITLKSEZ likes this.
  17. Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    "I used the timing mark on the crank pulley to align and make sure the rotor is at the 5 o’clock position."

    The above statement doesn't tell me a couple of things that may be clues.

    Was the #1 at the top of compression stroke when the timing mark was aligned? Was the #1 plug wire at the "5 o'clock position" mentioned?

    Also, have you actually confirmed there is no spark at the plug ?
     
  18. Yes the rotor was in the 5 o’clock position when on the timing mark and the#1 wire was in that spot. I did check and no spark thru the plug wires. I went out at lunch and looked at the dwell, with the points on the top of the lobe the points are at .020. When I rotate it off there is a large gap in between the lobe shaft and the connections to the points, I adjusted that to ride closer with the points closed and when I did the points are way too far open. I know this may not be the correct terminology but trying my best. I will adjust the points tonight after work and take my time to get things correct.
    Marty
     
  19. Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    Marty,

    Did you understand the first question?
     
  20. Yes, number 1 was at the top of the compression stroke when the timing mark on the pulley was aligned.