Calling all ignition guru’s

Discussion in 'Sparky's corner' started by 94IDI, Dec 21, 2019.

  1. 94IDI

    94IDI Jared

    Hey fella’s,

    I’m continuing to work my way through maintenance and upgrades on ‘Ol Lucy here.

    I recently got her back from my resto mechanic who installed Wilwood discs all the way around, a Muncie M-23, and a gearvendors overdrive.

    She has been GREAT to drive these last few weeks. Back and forth to work a couple of times a week with no troubles... until now.

    I got home from work the other night. Parked in the garage and went to bed... no trouble to speak of at the time. And then I come out to the garage to crank her up, and here comes the trouble...

    I’ve got normal sounding starter crank. But no fire. I cranked until I could smell fuel and then called it quits. She already has new spark plugs (less than 500 miles) with correct gap. But I pulled a few anyway and they look great still and still have good gap (albeit covered in unburnt fuel at the moment). So I decided to pull the distributor cap and have a look. The pics are posted below.

    Two questions:
    1. Can anyone tell me all about what kind of distributor/ignition system this is? It appears to be a completely OEM style points and coil setup,... but my eye is un-trained.
    -are the points corroded enough to provide a no-spark condition??

    2. Id like to assess the condition of resistance on the coil, but can’t find a part number in this ignition coil. Does anyone know how much resistance I should be showing on this coil... primary//secondary windings?

    Attached Files:

  2. mrolds69

    mrolds69 "The Cure"

    It looks like a stock ignition. At the least, the cap is toast, so probably the points are NG, too. Condensers just go for no reason sometimes. Because it had been running ok, I would look closely at the wire from the distributor to the coil. If that wire is broken, or burnt, or if the insulation is gone on it anyplace, it will ground out and be a no start condition. If you have a tach, you need to trace the wire from the coil to as far as you can see for the same reason. I doubt it's the coil.
  3. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Could it be a 12 volt system running on points? What is the + coil voltage in "run"?
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If you have a 12 volt test light, hook it between the - side of the coil and ground. Crank the engine and watch the light, it should flash on and off. If it doesn't, it indicates a problem with the points.
  6. 12lives

    12lives Engage! - Jean-Luc Picard

    Even a crappy cap rotor and points will try to fire, especially since it ran great the day before. Something happened, like a broken wire. Make sure you have power to the coil - What Larry said - do this before replacing parts: To test the system for proper functioning requires a volt meter. Connect the voltmeter between the positive side of the coil and ground. Turn the ignition switch to the run position. The reading should be 5.0-5.5 volts. It is important that the ignition points be closed for this test. If the points are open, the voltmeter reading will be full battery voltage. Bump the engine over until the points are closed, and check again. Again, 5.0-5.5 volts is the normal reading with the engine stopped, ignition key in the run position, and the voltmeter connected between the positive side of the coil and ground. The second part of the functionality test requires that you pull the coil wire out of the distributor, and ground it so the engine will not start. With voltmeter connected as before, crank the engine continuously, and observe the voltmeter. The reading should jump from the previous 5-5.5 volt reading up to 9 volts minimum. If it does not, it indicates a problem with the shorting switch inside the starter solenoid, or a wiring problem between the "R" terminal of the solenoid, and the coil. This will result in hard starting when cold.
    If you don't have a meter, just take some wire, turn the key to run, and see if you get a spark when you touch the wire from ground to the + side of the coil. Report back.
    BTW is that spider webs in the cap? Or is it in the plastic?
    bostoncat68 likes this.
  7. 94IDI

    94IDI Jared

    Hey good morning everyone and thanks for all of the information!

    The problem was a classic case of being a new-guy... Frank's reply from yesterday spurred my brain to realize that I had disconnected the tachometer to have it repaired (thanks Scott Moody). As soon as I realized that, I didn't even have to trace the tach wire... I went straight to the end of the wire that is in the car, and knew what I would find... Sure enough, the disconnected terminal was resting against the metal underside of the consollete. I put a piece of tape over the end of it, and the car immediately fired up as normal making me feel like quite a dummy.

    Given how crappy all of my ignition parts look though, I'm planning to go ahead and replace the coil, cap, rotor, and condenser while also scouring the forum for the best HEI solution... I think I'm ready to make that switch.

    Thanks a lot for all of your help guys. It's a comfort to know this resource exists... Feel free to chime in if any of you have an HEI setup. I'd love to get more info.

    mrolds69 likes this.
  8. mrolds69

    mrolds69 "The Cure"

    I'm glad you got it fixed, Jared. Sometimes you get lucky!
  9. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I have an HEI distributor for a BBB I'm trying to sell. PM if interested.

  10. Mike Jones

    Mike Jones Platinum Level Contributor

    Personally, I would keep your original distributor and install Lectra Limiteds' breakerless electronic ignition. That factory distributor, like Larry talks about in his Power Timing your engine, has a built in mechanical advance that was engineered specifically for your car. If your timing is otherwise good, I would just replace the points. I removed an MSD ready to run and went back to my factory distributor with a LL breakerless set up and I am very happy. Did all of the things Larry discusses for limiting advance including the vacuum advance limiter and kept the original set up. The engineers knew what they were designing when they set these up. Just my opinion.
    Brett Slater and BuickV8Mike like this.
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    First see what distributor part number is currently installed in the engine. It's a 67 GS400 with a 70 455, so who knows what's in it.

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