Register now to get rid of these ads!

Technical Early Hemi Power to Coil but No Spark?

Discussion in 'The Hokey Ass Message Board' started by tartar_sammich, Jul 12, 2018.

  1. Hi guys. A few days ago we took the '37 with the 354 in it across the street for its first drive and it ran very well. After we were done, we put it up and went to bed, and the next day it would not start. Prior to the test drive, there were times when it would not start (this occurred more and more frequently up until it quit), then suddenly fired right up and ran fine. Now, it doesn't even try to start. Just cranks and cranks and cranks. The engine has fuel and good compression, and the rotor is turning. I'm not very knowledgeable in the realm of electricity, but I know a few things as far as the ignition system goes. As for our wiring situation, it is just a temporary setup to get the car to run as we are not quite to the point of installing the wiring harness, but it has worked fine up to around the point we moved the battery to the trunk. I don't believe that this is the issue, but at this point we will try anything. For the switch, we have a battery kill switch (https://www.summitracing.com/parts/sum-g1432/overview/) with a hot wire from the battery on one side, and the wire from the + terminal on the coil and fuel pump connected to the other. To crank it, we have a trigger connected to the small starter post and the hot wire from the battery connected to the kill switch. The + terminal on the coil has the wire going to the kill switch and the red wire from the distributor connected to it, and the - terminal has the black distributor wire. If you need a picture of this, let me know. When the switch is flipped, the fuel pump runs, the starter has power, and the coil shows 13 volts in the on position and 11 or so while cranking. Both terminals on the coil show the same voltage. I tried to test the coil using a test light, the positive terminal stayed lit and I believe the negative did as well. I thought that it should pulse while cranking. I thought this meant a bad ignition module, so ultimately we replaced some things. I know it's not the way to go about it, but at least we've eliminated the possibilities of a bad distributor or coil. Here's what we've done to try and fix it: Swapped the coil with one that we know is good, got a new distributor (ours was still under warranty), made a new coil wire, and stepped up to a larger gauge on the wire going from the + battery terminal to the switch. I also bypassed the switch with a wire going directly from the battery to the + terminal on the coil and still no fire. The battery is grounded to the frame in the back, and the engine is grounded from the header to the frame up front. I have not put the test light on the new coil yet, I was frustrated when the new distributor and coil did not fix it and am in the house now thinking and asking you guys for help. I hope it's something simple that I'm overlooking, but I need some help to figure it out. Thanks guys.
     
    Last edited: Jul 12, 2018
  2. Figured I’d go ahead and give a visual.
    Here’s the switch in the disconnect position:
    [​IMG]
    The blue wire is for the fuel pump, and the coil wire goes there too but it is not connected right now. The clip is for the starter trigger, tried it on both posts. Red wire comes from the battery.

    Here’s the coil:
    [​IMG]
    - wire goes to the distributor and the two + wires go to the switch (black) and distributor (red).


    Sent from my iPhone using The H.A.M.B. mobile app
     
  3. What kind of distributor, you mentioned a module; so it's not a points distributor?
     
  4. No points. It’s a Pertronix Flamethrower distributor with the Ignitor II module.


    Sent from my iPhone using The H.A.M.B. mobile app
     
    Register now to get rid of these ads!

  5. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Does the coil have the correct primary resistance for this module?
     
  6. manyolcars
    Joined: Mar 30, 2001
    Posts: 7,379

    manyolcars

    Pertronix go bad too. Voltage spikes kill'em
     
    Last edited: Jul 12, 2018
  7. firstinsteele
    Joined: Jun 13, 2013
    Posts: 646

    firstinsteele
    Member

    Your voltage may be too low. Charge the battery to 13-14V and try again.

    Ben
     
  8. I’m sure they do, but both the coil and distributor are brand new. I mean, even with the new parts, the engine doesn't even hit once.


    Sent from my iPhone using The H.A.M.B. mobile app
     
    Last edited: Jul 12, 2018
  9. It should have been fully charged, we left a charger on it all night last night, and the starter spins fast. I’ll leave the charger on it again tonight.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  10. It should. The coil is a Flamethrower II which is what Pertronix says to use with the module.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  11. manyolcars
    Joined: Mar 30, 2001
    Posts: 7,379

    manyolcars

    and no ballast resistor
     
  12. Yep, no ballast resistor.
     
  13. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Is the distributor grounded good?
     
  14. I hooked the test light to the positive coil terminal and touched the distributor housing and it lit up, so yes. I think.
     
  15. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Have you tried to hook the coil positive side of the coil to the battery side of your disconnect switch?
     
  16. In a different way. Ran a jumper from the positive battery post directly to the positive side of the coil to bypass the switch, still no luck.
     
  17. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Maybe move your engine ground wire from the header to a bare spot on the engine block.
     
  18. I just went back outside and tested the coil. The light does not blink when touched to the negative side while cranking. I'm pretty sure that's not right. Theres no way the new distributor and coil are bad. What could be causing this?
     
    Last edited: Jul 14, 2018
  19. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Is the distributor turning/
    Sorry someone had to ask. :D
     
  20. I should also mention that we forgot to put an engine ground on the car until just a few days ago, after it had run in its present state. Boneheaded, I know, but we have one now. I'll try moving it to a better spot.
     
  21. Affirmative!
     
  22. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    To test the coil disconnect the distributor leads, then take a jumper wire connected to the negative side of the coil and tap it to ground on and off .
     
  23. What am I looking for to happen? Do I put the test light into the middle terminal of the coil to check for spark?
     
  24. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    No put the coil wire in it hand hold it about a 1/4 inch from a good ground.
    The coil should spark every time you remove the negative jumper wire from ground.
     
  25. Just tried it, spark was present.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  26. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Try a ground wire from your distributor to good ground, if still no spark it has to be a problem with the module in the distributor.
     
    hotcoupe likes this.
  27. What should the spark have looked like? Should it have been big and bright? What I saw was pretty small. I'll try the ground wire tomorrow, it's late and I don't want to wake the neighbors if it fires.
     
  28. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    Should be a nice blue spark and jump 1/2 inch.
     

  29. Here’s a terrible video of something that I’m probably doing wrong. After I took it I realized that the breather probably wasn’t a good ground and tried it on the distributor, it was a little bit easier to produce a spark but it wasn’t much bigger.


    Sent from my iPhone using The H.A.M.B. mobile app
     
    Last edited: Jul 12, 2018
  30. saltflats
    Joined: Aug 14, 2007
    Posts: 8,437

    saltflats
    Member
    from Missouri

    What is that spark that I am seeing just under your fingers in the lower left corner of this video?
     
    tartar_sammich and Truck64 like this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2013 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.