No spark front cylinder only

[Cooter]

I submit this problem to the Buell Brain Trust (BBT)TM for your consideration, plenty of smarter people on here than I am, and I've lost enough hair already

Bubbles '05 XB12-Scg, 10k-ish miles. All stock except K&N, Drummer, and matching IDS ECM. Very well maintained, never sits for more than a week or 2 at a time, and the last thing she put in was clutch plates and an oil change about 2 months ago. It's been running perfectly since she bought it, until now

90* clear day, 150 miles into a ride and over 40 miles from the last fill up, her bike lost spark to the front cylinder only. First intermittently but then completely in less than a couple miles It will still sometimes, but only very occaisionally fire on both cylinders, but mostly nothing.

I did all this under a shade tree in the dirt near Caliente, CA, so forgive the improper procedure

I pulled out the plug, grounded the electrode, and no spark at all while it runs on the rear cylinder and the rear cylinder runs dependably (got 50 miles at 60mph to a hotel on the rear only, yay Buell)

It has NGK DCPR8-EIX plugs that are new and very clean. I even swapped on another plug from my XB just in case. Still no spark in front. Her plug fires fine on my bike ('08-STT) and HOLY CRAP the DDFI-3 spark plug cleaning feature is a surprise when you turn the key on. I will NOT forget that anytime soon

Both plug wires ohm fine, I made a new 7mm plug wire for the front (Thank YOU Mr Rodriguez and your '85 Old Cutlass Supreme hot rod project), and even swapped the plug wires front to rear, No spark in front.

With a plume of a grass fire in the distance... I swapped coils from my running bike (same part #). No spark in front, and mine still runs great with her coil in it. Even though an ignition coil (step-up transformer) does not need any chassis ground to work perfectly, I grounded the mounting bolt anyway, no change.

I ohmed both the primary wires between the ECM and coil. The front one is the one with the "dyno loop". They have good continuity end to end, infinity to ground, and I wiggled the crap out of them while doing it. I even pulled the pins from the connector and completely bypassed the front primary wire with a new length of wire to be sure. No change.

Coil power wire is fine, and both cylinders would be affected anyway.

I used ECMDroid to fire the front and rear cylinder. Spark in rear, no spark on the front.

Thinking the driver in the ECM that fires the front plug was overloaded/bad, I rode 360 miles at 90MPH to pick up and replace the stock OE ECM for the bike. No change.

I eliminated the CPS as the cause because it has only one output (to the ECM) where the ECM then uses that signal to time and split the spark primary signal. So if there was a CPS issue, both cylinders would have to be affected.

I'm not one for replacing parts as a guess because thats lame, expensive, and time consuming but thats what I'm down too. Since the bike is back home now, I think I have another (the 3rd) coil to swap in Whats Satans phone number again? I have something to sell him

TL;DR
No spark in front cylinder only, and I've tested or replaced everything except the fuel pump

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One free Buell drain plug O-ring to the first person to get it right!! You have to get it in person, but it does come with a cold beer and a long talk about motorcycles
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[Barrett]

shaughn: i absolutely hate any sort of mechanical problems on a trip and believe me, i feel for you and the hassle you went thru over this. i thought i had your answer till you mentioned swapping the ECM for another, i'm assuming....known good one.
think of that dead front cylinder in these terms: if it has spark...timing....compression....and fuel, it has no choice. it must and it will run. from what you mentioned, i believe you're missing either timing or spark. i'm sure you saw raw fuel on the plug and heard and felt compression out the spark plug hole during this ordeal. you've eliminated the plug and wire as it fired in your bike...swapped the coil to another bike and it worked fine....which leaves timing and spark source. both supplied by the ECM.
the CPS wouldn't trigger the ECM for one cylinder and not the other.
my money is on the ECM....the harnesses for same....something askew in the connections for same. the front injector is a red-tipped job. any chance the injector signal wire chafed and shorted onto something atop the motor?
PS-glad you and errin are back home and safe and sound. and so sorry to hear about this mess.

[34nineteen]

I’m still blaming the CPS or the something up with the timing cup. If I’m not mistaken, the CPS also tells the ECU when to fire the injectors. I think a Noid light is used to test the injector signal? If the ECM isn’t firing the coil properly, it’s probably not firing the injectors properly either. I still doubt 2 ECM’s are going to have the same problem. Improbable, but not impossible.

Do you need me to pull the CPS from my bike and send it to you?

[Cooter]

Thanks John We got through it, Bubbles has an undaunted positive attitude Problems can be frustrating, and this one sure was unexpected! How many times have I said I like Buells because they are hammer simple? Well, my dang hammer stopped working and I can't figure out why! I feel so dumb, derrrrrr

I'm positive its 'no spark' because I can actually see the spark plug not firing. It's going to be a weird anomaly. But whats left? I dunno.

Your offer is awesome as is your help, Aaron I removed the CPS input pin at the ECM and it will still fire the rear and not the front with ECMDroid?

[Cooter]

I even got to ask the bikes PO about the condition of the OE ECM. "Did he put on the Drummer and IDS ECM chasing an issue?" He said no, it ran great before and after he had Jacob Stark do all the work when he used to have a shop, and I believe him.

He's the one who gave us a big box of parts, he's the guy that drove 250 miles to pick her and the bike up, he's awesome...

But to answer your question, no I haven't checked the injector outputs. I agree that it's not impossible to have 2 bad parts (they are used...) but it took me a lot of convincing to suspect the solid state ECM in the first place. I'll mess with it today, perhaps a clear head prevails

[34nineteen]

Thanks John We got through it, Bubbles has an undaunted positive attitude Problems can be frustrating, and this one sure was unexpected! How many times have I said I like Buells because they are hammer simple? Well, my dang hammer stopped working and I can't figure out why! I feel so dumb, derrrrrr

I'm positive its 'no spark' because I can actually see the spark plug not firing. It's going to be a weird anomaly. But whats left? I dunno.

Your offer is awesome as is your help, Aaron I removed the CPS input pin at the ECM and it will still fire the rear and not the front with ECMDroid?

This one is going to be one for the books. Its going to be something ridiculously stupid... you know this, right? Sort of like the needle in my carb.




It could be that you have a preexisting condition that is damaging a portion of the ECM, which is causing the ECM to not fire the coil correctly. Maybe you are trying to resolve the symptom, and not the actual problem. I wouldnt be surprised to have a ECM go wacky, but 2 with the same problem is highly unlikely... unless the bike is damaging the ECM's somehow.

[outthere]

Checked all the fuses? Just reaching

[Cooter]

This one is going to be one for the books. Its going to be something ridiculously stupid... you know this, right? Sort of like the needle in my carb.

I totally agree, working in the dirt sucks


It could be that you have a preexisting condition that is damaging a portion of the ECM, which is causing the ECM to not fire the coil correctly. Maybe you are trying to resolve the symptom, and not the actual problem. I wouldnt be surprised to have a ECM go wacky, but 2 with the same problem is highly unlikely... unless the bike is damaging the ECM's somehow.

This too ^^^
In the search for the cause, I did find some typical Buellizms I fixed and I didn't bother to mention so as not too distract the point.

One was the ignition fuse was smashed into the fusebox but next to the connectors, not in them. It was HOT but never blew. I replaced it anyway.

Another was the primary wire to fire the coil for the front cylinder has a "dyno loop" in it so the front and rear wires don't cross-signal from being the same length. Right at the loop, it had been sitting outside of the loom, right on the battery tray and wore a little hole in the insulation. I swore that could have overloaded the driver in the ECM and caused an ECM failure EXACTLY like I was having.

To your point Aaron, thats what convinced my to drive 240 miles to get the other ECM. Imagine how depressing it was to do that and STILL have to stay in Bakersfield another night

[Cooter]

always my pleasure shaughn. for what it's worth if it would help...i have my 2006 XB9 cityX....my 2008 XB12 black lightning....my 2008 XB9 cityX....my 2009 XB9 cityX here in my building. if it would help solve the mystery and if it would be match to Bubble's bike...i could pull the ECM off one of your choosing, send it out to you, and you could plug it in and see if it solves the problem. let me know and happy to do that for you.

Man thats so generous, Thank YOU! Hopefully I'll have it sorted soon to at least KNOW, unequivocally, exactly the part I need. Tick tock! haha

[Cooter]

Oh jeez...

It was something really, really, stupid that made this harder than it needed to be.









ME. I'm the stupid thing that made this so difficult


When I pulled off her coil to swap in mine, I put an "X" on hers just in case I got distracted holding identical parts in my hands and mix them up by mistake. Smart, right? Well.... Then I got distracted and mixed up which coil I put the "X" on and put mine back on my own bike, thinking it was hers when mine ran fine (of course it did, it was MY coil), I eliminated the coil as the cause and just left it on my bike. If I had even swapped them back I would have found my mistake and saved 2 days of hanging out with homeless people in Bakersfield, not to mention the extra grey hairs!

I'll take my lashings now But a HUGE THANK YOU to all you helpful and oh-so-smart peeps on here for reaching out and offering your knowledge and even willing to dismantle your motorcycles for me!

Bubbles thanks you too