2005 sportster ignition coil Question?

Discussion in 'Electrical' started by Ultra Classic, Jun 4, 2011.

  1. Ultra Classic

    Ultra Classic Member

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    Okay i know this is a dead horse but i am still a little confused by some of the posts on testing the ignition coil on a sportster? One post said to leave spark plugs in the cylinders for compression reasons and just put another spark plug in the wires to see if it produces a spark when turned over. This is my first step in determining why my bike won't start. And my other question is when i test the ignition coil primary and secondary with my ohm tester. What exactly is it testing if not hooked up to battery? Am i testing the magnetic part in the coil? Is this correct? Thanks for any clarification on this.
     
  2. Jack Klarich

    Jack Klarich Expert Member

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    Harley Davidson Community this may help, if you test for spark at the plugs and they are out of the heads be sure to ground them:s Lisle 19380 Spark Indicator
     
    Last edited: Jun 4, 2011
  3. Hoople

    Hoople Account Removed

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    Is this a factory stock 2005 coil. Does it have 4 wires going to it which would indicate it has Ion-Sensing electronics?

    Using an ohm meter to test a coil does not tell you a whole lot. It can pass ohm meter tests and still be bad. About all it tells is if the coil windings are dead short or wide open. It tells you nothing about having a few shorted turns or about it's di-electric strength.

    I would leave both spark plugs installed in the heads. Then using the Lisle spark indicator, see if you have spark on each spark plug wire.

    Do you have spark on EACH wire? If No on Both wires, check to see if you have battery voltage going to the coil. It is probably missing because I doubt both primary windings are bad.
     
  4. Ultra Classic

    Ultra Classic Member

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    First off thanks for your reply. It's is a factory coil and there are four small wires going into the coil. The battery is good and tomorrow i'm going to purchase a Lisle spark indicator since you mentioned it. I was just letting the spark plugs hang down while i cranked her over to see if there was a spark but i'm guessing this is the wrong way of going about it. What does the ion-sensing mean? I'm at the point now where i want to start working on my own bikes so i'm all ears to what ever you have to say about my problem. Thanks again for your help.
     
  5. BUBBIE

    BUBBIE Well-Known Member

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    The BASE of the spark plug HAS to be Grounded for the spark to JUMP across the electrodes..... Hanging them will NOT amount to a CHECK,,,, the plug thread area must touch the metal on the cyld. head.. your New tool (plug) will have a grounding alligator clip....Make sure it is grounded

    signed....BUBBIE
     
  6. Hoople

    Hoople Account Removed

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    For your type of problem, I would give this model a try. It places a spark demand on the coil and forces it to jump a gap. Dial in a .040" -.050" gap and see what happens.

    Toolfetch.com


    Also what Bubbie says is true. You can't just let the plugs hang.
     
  7. Hoople

    Hoople Account Removed

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    Unlike the early dual fire ignitions, the late model 4 wire coils are actually 2 coils in one package. Ion-sensing allows the ECM to sense spark knock and retard the spark advance on the fly. There is 1 wire to transmit info to the ecm for ion-sensing. There is 1 power feed (12v) wire to the coil(s). There is 1 trigger wire for the front spark plug and 1 trigger wire for the rear cylinder.
    So a total of 4 wires.

    Because late model engines are single fire and also do not have cam sensors, there must be a way to phase the ignition to the crank since there are 2 TDC's for each complete power cycle of a 4 cycle engine. (720 degrees of crank rotation for just one power stroke) These ignitions do not fire on TDC of the exhaust stroke (valve overlap).

    Therefore to phase the ignition, the ECM detects the "slowing down" of crankshaft speed during cranking to determine ignition phasing. The plugs must be installed in order for the engine to build compression. If the plugs are removed, the crank will just free wheel and no slowing of the crank will take place, so spark will be inhibited.
     
  8. Ultra Classic

    Ultra Classic Member

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    Okay it's confirmed that i do not have current going to the plugs. I did purchase a spark plug tester to verify this. I have tested the battery and it's putting out a little over 12 volts. Now i have to correct myself when i said that there were 4 wires going into the coil from the battery but there is only 3. I turned the bike on to test all three wires to see if current was going to the coil from the battery and this is what i got. The two outside wires were registering .1 and the middle wire was at around 12. I hope this makes sense to someone so you could give me a better idea at narrowing this problem down.
     
  9. Hoople

    Hoople Account Removed

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    Is this 2005 Sportster factory stock. Does it still have the factory Delphi ECM. Does this bike have a Power Commander or Fuel Pack installed. Regardless of what the check engine light is telling you, have you checked to see if there are any stored DTC codes codes. Have you checked All of the fuses using a meter. Do you hear the fuel pump prime for 2-3 seconds when you turn on the ignition and flip the kill switch to run.

    Was this bike running fine one day and then failed to start on the following day,, Or was the bike running fine, and then it quit in the road, would not re-start and had to be towed in.

    When you checked for spark, both plugs were installed in order to have compression.
     
  10. Ultra Classic

    Ultra Classic Member

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    It is a factory sportster. Nothing fancy to it. It also has a carburator. I took it out of the garage as i always do to ride it, turned it on, cranked it over, she started to run but then died. I tried to start her again and.....nothing! I hear a sound similiar to a fuel injector priming when i turn the key on but that's was a normal sound every time i started the bike up. Both plugs were in and the spark tester does work since i tried it on my ultra just to be sure. No i have not used a meter on the fuses but the fuses themselves were fine. I'm just not getting current from the coil to the plugs. What do you think?