Strange Starting Issue...Long post but important..

[ksmike]

I was having starting issues with my 2010 Bulldog. EFI, 10,000 miles , stock electronics.....

When trying to start it, the starter would quit after one revolution occasionally and the problem got more frequent as time when on.

After first diagnosis I realized that the EHC was dropping out and rebooting so to speak. I first thought it was a dragging starter problem pulling down the voltage so much that the EHC was being affected. Compression releases were working so I took the plugs out to try to lessen the load on the starter, but the starter would still only turn about one revolution before it quit. All the lights on the EHC would go out and then come back on, and it would return to normal. Then the run button would have to be pushed again before it could try to be started again.

I tried it with fully charged battery and also boosted battery, and it still would kick out after one revolution.
Tried new heavy battery cables….did not help
Tried a new EHC…..did not help
Tried a different VFI module …..did not help :bang::bang:

If I ran a jumper wire from the battery to the starter solenoid it would turn over normally…hmmm

Unhooked the crank sensor…..engine would then continue to turn over. but not start ( no spark trigger) hmmmm interesting maybe bad crank sensor? I didn’t have another crank sensor but it seemed to check ok , so I continued on.

After studying the electrical diagrams I decided to unplug the primary wires to the coil…..doing that, the engine would turn over normally..…maybe bad coil?? Shorted??

Put new OEM S&S high output coil on it ….still same problem…. EHC would drop out after one revolution….dammit….….:bang::bang::bang::bang:

With trial and error…found that unhooking the front cylinder primary wire to the coil would let it turn over normally….what the hell….???

Put new spark plugs in it….still same problem…would only turn over one revolution and the EHC would drop out, stopping the starting sequence…..

Just out of curiosity I put a suppressor (ferrite bead) on the coil primary wiring before it feeds back into the VFI……it would then turn over normally….interesting …problem seemed to be fixed…

I found the problem, or at least corrected the problem….any guesses to what really fixed it??? (Hint....the ferrite bead on the coil primary wiring was really just covering up the problem)

 

[DRBarnhart]

Ignition switch wire(s) too close to the primary wire/coil?

Dennis

 

[ksmike]

Ignition switch wire(s) too close to the primary wire/coil?

Dennis

Good educated guess, and in the correct area.....but there was actually a bad component.....any more guesses???

 

[FrankBDPS]

Thanks for the info and I am sure some one smarter than me will figure it out. Do you have a couple of pics of that bagger you can post? I am thinking about building one. Thanks

 

[ksmike]

Here it is.

 

[Sven]

Thunderheart ign box?

 

[Jwooky]

you put the suppressor where?

The blue /yellow wires feed the coil, not provide feed back. Are those the ones you mean?

 

[ksmike]

I put the suppressor just after the Red, Blue, Yellow wires come out of the EFI Controller. The only reason I put it there was that it was easily accessible under the seat. The suppressor that I put on is about 1" square.

FWIW when I refer to the EFI Controller, ECM, or VFI I am talking about the same thing.

Not to be confused with the EHC....

But the suppressor was just a cover up for the real problem......still no more guesses???

 

[GDOG_PITBULL]

Bad spark plug wires / high resistance?
G

 

[ksmike]

Bad spark plug wires / high resistance?
G

BINGO!!! We have a winner

The front cylinder plug wire was causing the problem. But the real interesting thing is that both wires ohm out at 770 ohms. I double and triple checked to make sure my finding was correct, and I could easily replicate the problem with the front wire. Even though the ohms were good, it seems the wire had lost its ability to suppress the EMI and it was getting back into the EHC causing it to shutdown. (the EHC controls the starting sequence on my bike) The suppressor that I put on the coil primary wires fixed the problem also, but I wanted to find the real culprit.

Anyway, I started researching new plug wires and checked out Magnecor's website. After reading through it and paying close attention on what they had to say about EMI causing problems with electronic engine controls I decided to give them a call.

Magnecor Race Wires

I contacted Steve at Magnecor and he was very helpful and got me set up with the correct wires for my EFI Bulldog. $57.00 delivered.

I went with the KV85 wires since they seemed to have the most EMI suppression. Part # 25101 They do have a 90 degree plug & coil boots but fit and look fine. It runs great and starts easily now.

The moral of this story is..... don't overlook the importance of good plug wires and their effect on the EHC in our Dogs. :up:

 

[Jwooky]

Bizzar......still don't get how the suppressor on the coil feed helped if it was the plug wires because the coils are run by the EFI module not EHC?

 

[Brew]

Way to keep at it and track down the issue instead of letting it stay masked... :2thumbs:

 

[ksmike]

Bizzar......still don't get how the suppressor on the coil feed helped if it was the plug wires because the coils are run by the EFI module not EHC?

Thats a good question...

Maybe the EMI was feeding back through the coil, or the coil primary feed was acting as an antenna of sorts picking up the EMI and feeding it back into the EHC via the EFI module? Don't know that for sure with the limited electronic tools that I have. (just a good Fluke meter)

But..the suppressor(ferrite bead) on my coil primary definitely makes a difference. I looped the primary wires through the ferrite bead one time and it did the trick.This is the type of ferrite bead that I used. Only about 1" square.

But that being said, I think the Magnecor plug wires are the way to go.

 

[Jwooky]

EMI can be tricky, and can find some strange paths. Best way to deal with it is to design the modules to be impervious to it.

Another way to suppress it it to wrap the antenna (plug wires in this case) with foil, then ground the foil.

Obviously, you wouldn't do this for a permanent fix, but for diagnostic purpose.

 

[Sven]

Did you swap coil wires to the other side? Also, watt are the odds a quick 'drag on the starter' is to pull the coil wires off without grounding them, see if the starter spins the engine? This way you loophole pulling the primary off the coil, you are completing a circuit with the coil wires grounded, correct?

So if it's coil wires all along and both have the same resistance? Numbers don't lie. Unless you wet the wires with a mist and that one wire has resistance equal to the other wire, but did you really find the problem no jump to ground with the water misting at them? That wire wind in the box is a frequency buffer. Way too much noise like my posts and a poor signal meaning and here you are with a band-aid that is down the chain or line somewhere at a jobber still, not a wire with equal measurements? Just thinking out loud is how electrics mess with my walk at it.

 

[ksmike]

Something else that I did previous to changing the plug wires was put new spark plugs in.

Did you swap coil wires to the other side? Also, watt are the odds a quick 'drag on the starter' is to pull the coil wires off without grounding them, see if the starter spins the engine? This way you loophole pulling the primary off the coil, you are completing a circuit with the coil wires grounded, correct?

I did not swap the wires from front to back, which would have been the proper thing to do to further troubleshoot the issue, but it was obvious the front plug wire was doing something different. And metering the wires for ohms may not tell the complete story as well since my meter only puts a couple of volts on the wires when checking for ohms, while the coil puts out 20,000 or so volts...

So if it's coil wires all along and both have the same resistance? Numbers don't lie. Unless you wet the wires with a mist and that one wire has resistance equal to the other wire, but did you really find the problem no jump to ground with the water misting at them?

I didn't do the mist test.....starting was the problem, not running, but the water may have shown something also.

That wire wind in the box is a frequency buffer. Way too much noise like my posts and a poor signal meaning and here you are with a band-aid that is down the chain or line somewhere at a jobber still, not a wire with equal measurements? Just thinking out loud is how electrics mess with my walk at it.

Yes, the ferrite bead suppressor is just a high frequency suppressor and a band aid, so I kept on searching, and the problem stopped when I changed the plug wires. I really have to wonder if the OEM plug wires were good enough at keeping the EMI out of the bike electronics.

 

[Sven]

Yes, the ferrite bead suppressor is just a high frequency suppressor and a band aid, so I kept on searching, and the problem stopped when I changed the plug wires.

JMO, but there is no bow to the EE Smilie, but I think you're a genius coming up with a wave length. Watts a ferrite? I had to look that part up. As soon as I saw the wave, the signal = Bingo it starts? Brilliant, Mike! 'Svenny likes it.'

I really have to wonder if the OEM plug wires were good enough at keeping the EMI out of the bike electronics.

Well, I really have to wonder why all this 'and my BD starts right up I turn the key back on.' The way I'm being schooled here, (teach) is to wonder, hey, I just bought a BD and my bike cuts out/stopped running/you/ground wire glows/.78v with cable on/12v cable off. What is going on with this bike?

I would think as long as the bike is running, that bad signal is still there with key on, right? Once you turn the key off, that grounds the bad signal, you turn the key on, that goes back to a good signal and starts. Key still on and you crank it, that is the same wave at the coil. So having the ferrite bead placed at the primary (the out wire to the coil from the spark box) where you placed it, I would have a backup wire in a way going to ground. See that over engineer that cleaner wave length the spark plug wire needs?

I mean, one combo after the other and it's all about no start/restart conditions. I have yet to change my spark plugs with my over 10yr/old plug wires. And is there a filter at the spark plug? Yes, but for radio static with the car next to you? Is there a buffer in the plug wire? No. Is there a buffer in the coil? No. Is there a buffer between coil and spark box? No.

I am knocking on the door of the spark box. Thunderhit is hit with watt? No buffer or say, no one way diode to stop the natural back and forth in the wire is AC, correct? For every action? You know for sure the ping is not going back in the box with that IC chip having one way directions out and in at that truth table round. That means that one plug wire still ran a path back to the spark box, pings back to the coil and you set a buffer there at the primary coil wire?

I now have to believe if I didn't read it with my own eyes, you are saying you changed plug wires and all is well. Then, I would have to think that not too many plug wires have been changed since the bike was new, WATT ARE THE ODDS a lot of no starts might be an original plug wire? I would thing every BD owner would start swapping out for pull 'over to the side of the road odds.' You say so and no buffer is used, then WOW, schooled again.

I am almost convinced either you start selling a BD kit at the primary coil side so the purists can keep their original coil wires, (JK). Or invest in spools of spark plug wires, (jk again), but really, something is up with those incomplete black boxes not having a buffer out of that wire to the coil, yes? Possible if I knew a few parts like yourself? I wish I had the math for this or I'd be an EE, this is some fun stuff.