Author |
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Lovejulian
| Posted on Saturday, July 19, 2014 - 06:20 pm: |
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Hey this might just be a general mechanic question, but here it is.I have a 99 S3 Thunderbolt. The kill switch is hooked up to the coil and thus giving my ignition system power and powering up the coils. I tested the power with a multimeter and the plugs are getting power from the coil, but they won't spark. What would cause plugs to be getting power but not sparking? I tested the spark on the frame and nothing happened. Also, they are correctly spaced. |
Lovejulian
| Posted on Saturday, July 19, 2014 - 07:25 pm: |
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Also, I test the coil and it is good. |
Buell_bert
| Posted on Saturday, July 19, 2014 - 11:20 pm: |
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Take an ohmmeter and test the resistance between the plug wire and to the electrode maybe??? Do this to both of them of course. Make sure they are both the same too. |
Lovejulian
| Posted on Sunday, July 20, 2014 - 12:59 am: |
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Yes I checked the ohms. Both the front and the rear are reading around 14.5k |
Andersonhdj
| Posted on Sunday, July 20, 2014 - 03:41 am: |
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Plugs burned shiny black perchance???? |
Lovejulian
| Posted on Sunday, July 20, 2014 - 04:56 am: |
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No the plugs are brand new as well as the plug wires |
Gabby_duck
| Posted on Sunday, July 20, 2014 - 09:12 am: |
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ohm's check is good but not always 100% that the coil will fire under a load.If it was mine I would change the coil. I run in to this with {COP} coil on plugs all the time. |
Gabby_duck
| Posted on Sunday, July 20, 2014 - 09:16 am: |
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P>S continue from above make sure per your maintenance manual that the coil is geting proper voltage. |
Akbuell
| Posted on Sunday, July 20, 2014 - 10:37 am: |
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Check and confirm that there is a good ground between the cyl heads and the frame. Do not forget to check for ground between the cyl heads and the battery negative terminal. If that is good, don't hesitate to check the ign system starting at the crank position sensor, or whatever is appropriate for your system, which I am not familiar with. The coil may not be getting a signal to 'fire' the plugs. Hope this helps, Dave |
Lovejulian
| Posted on Sunday, July 20, 2014 - 12:55 pm: |
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@Gabby duck That's what I was considering when checking the coil. Even though I was getting the correct current flowing through there when the bike is "on", without turning it over, it may not "fire" or give more power to the plugs when it is turned over causing it to not spark. @Akbuell The cylinder heads are grounded and I had my friend (a local motorcycle mechanic) make sure that the digital ignition system was in the correct firing order. But even if it wasn't in the correct firing order, wouldn't the plugs still get a spark when it's turned over? |
Akbuell
| Posted on Sunday, July 20, 2014 - 01:36 pm: |
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On my X-1, the ECU 'listens' for a signal from the CPS so it knows when to shut current off to the coil, firing the plug. If, for instance, the bolt that holds the trigger rotor to the cam were to come loose, the trigger rotor might not spin at all, or may spin too slowly to generate a signal. That is the sort of thing I was talking about. |
Gabby_duck
| Posted on Sunday, July 20, 2014 - 08:02 pm: |
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I have a bad coil and new coil in my shop right now. Both Ohm out the same one works the other dosn't. Make sure that your relays and on off switch on the bike is functioning correctly. |
Buell_bert
| Posted on Monday, July 21, 2014 - 09:36 am: |
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I just checked your first post. How are you checking the (I tested the power with a multimeter and the plugs are getting power from the coil, but they won't spark.) You have a multimeter that tests 20-40 thousand volts? What was the voltage you measured anyway? I have a couple nice VOM's and the highest any go is 1000 DCV and 750 ACV. |
Lovejulian
| Posted on Tuesday, July 22, 2014 - 04:47 pm: |
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Mine only goes up to 10k but when I hold my multimeter up to the plug wire and turn it over, it goes from 14.5v down to about 7v. I also tried running a separate ground to the battery from the coil and still nothing happened. I'm going to grab a coil that I know works and see if I can get a spark from that one. |
Buell_bert
| Posted on Tuesday, July 22, 2014 - 08:49 pm: |
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Ok so you are measuring primary voltage. If you have no spark you may not have any secondary voltage. Your voltage drop is mainly from cranking the starter I would think. What brand VOM do you have that has 10K VDC? |
Gabby_duck
| Posted on Wednesday, July 23, 2014 - 08:16 pm: |
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Lovejulian when you "grab that coil that works" have your helmet on and enjoy your ride. |
Lovejulian
| Posted on Friday, July 25, 2014 - 10:07 pm: |
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Okay so I got the new coil in and installed it and when I went to start it up, I got a loud "boom" (which I assume was a back fire) and then didn't start. |
Lovejulian
| Posted on Friday, July 25, 2014 - 10:29 pm: |
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Oh I forgot to mention that when I replaced the coil, I got spark on both plugs. |
Gabby_duck
| Posted on Saturday, July 26, 2014 - 08:23 am: |
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Big intake seal leak ,Timing,cam position sensor,leaking injectors,tps needing reset or replacement,reset adaptive fuel value or O2 sensor bad. Bad ECU. I don't know this bike but one of these could cause the back fire.Pull your plugs and make sure they arn't fouled.Also is your gas fresh if not drain it and add good fuel. |
Reepicheep
| Posted on Saturday, July 26, 2014 - 11:32 am: |
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Check the cam position sensor... trivial if you have a scope, a little harder with just a voltmeter. |
Lovejulian
| Posted on Saturday, July 26, 2014 - 01:37 pm: |
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So I was doing some studying in my service manual and realized that my bike doesn't have an ECM attached. It's not even there so would this cause the problem? Know where I might find one? |
Readyxb
| Posted on Saturday, July 26, 2014 - 03:41 pm: |
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You have a 1999 S3 Thunderbolt and it doesn't have an ECM attached? That would be a problem if the engine needs to run! What happened to the ECM? |
Lovejulian
| Posted on Saturday, July 26, 2014 - 06:37 pm: |
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I'm not sure. I remember before I did any work to the bike, that there were the ECM connectors on the wiring harness that weren't connected to anything. When I turn it over, the cylinders are firing, but it doesn't sound like it's getting fuel in there to fire them up. Because there is no ECM, would that cause the fuel injectors, air sensor etc to not function correctly? |
Readyxb
| Posted on Saturday, July 26, 2014 - 06:59 pm: |
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If I am reading your response correctly, your wiring harness has the two 12-pin ECM sockets, one black and one gray, but the ECM is not connected? If so, the engine will not run. Just take a look in the service manual at all the sensors that the ECM reads (O2, engine temp, air temp, throttle position, camshaft position) and what it controls (fuel injectors, ignition coils, fuel pump), in order to start and run and engine! |
Lovejulian
| Posted on Saturday, July 26, 2014 - 08:56 pm: |
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Yes it has the black one and then the grey one. I was reading my owners manual and that's when I realized that I didn't have one (first time working on a motorcycle). My friend says that he thinks that it's carbureted vs fuel injected and so it wouldn't need an ECM. Is that true? |
Readyxb
| Posted on Saturday, July 26, 2014 - 11:34 pm: |
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Hi, unless there have been some significant modifications to the bike (I don't know the bike's history), if you have the black/gray sockets with 12 pins each, then it needs an ECM. The previous years were carbureted, but in 1999, Buell introduced DDFI on the S3 Thunderbolt and X1 Lightning. The M2, however, stayed carbureted. Do you have a carburetor or fuel injectors? Is this a special project bike? Just wondering why the ECM is missing! |
Buell_bert
| Posted on Saturday, July 26, 2014 - 11:49 pm: |
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How the heck can you get spark with out the ECM??? Does anyone wonder??? Pardon my french. This seems a little different. |
Readyxb
| Posted on Sunday, July 27, 2014 - 12:03 am: |
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Definitely crossed my mind, which is why we need some history on the bike! Is it some project bike converted to use a carburetor?? Lovejulian - pictures, videos, and any bike history you can provide would be very helpful. |
Lovejulian
| Posted on Sunday, July 27, 2014 - 01:52 pm: |
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Okay here is what I think is going on. The previous owner just dumped it off on me cause he was done trying to mess with it. When I first got it, it would start, but it would only fire up one cylinder. Also, whenever I opened up the throttle, it would immediately die and it would die if I slowed the bike down to a stop without keeping the rpms up. The previous owner thought the bike was an M2, so he put a bunch of parts into it for the M2 instead of for the S3. The wiring harness was wrong, the throttle body is carburated instead of fuel injected, it didn't come with an ECM, the coil wasn't wired correctly, it was incorrectly timed because he got it fired up on one cylinder and it was running "good enough" to dump on someone else. So pretty much what I gather is that this person was an idiot. Since owning it, I have replaced the wiring harness, new spark plugs and new coil. So where I stand right now, I need a ECM and a fuel injected throttle body, time the ignition system, correct the fuel line and I should be good to go right? Hope this helps with the confusion. What I still don't understand, is how it fired up one cylinder before without an ECM and it is firing right now without one. Could it be that I am bypassing the ECM by wiring the positive into the kill switch and giving it power that way? |
Gabby_duck
| Posted on Sunday, July 27, 2014 - 04:51 pm: |
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are you able to drive this bike if so how fast and how slow,does it Idle back fire etc... |
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