WTH did I do?

[Macbuell]

Faulty ground cause this? Tighten up all wires. Worth a shot.

 

[sparky300]

Check & tighten the battery terminals. Do a load test on the battery, I believe output when running should be north of 12.4 vdc?

 

[Jasenko9643]

"06 XB12X, 9500 mi, breather mod"

you state breather mod? what do you mean you installed a catch can? cut holes on your intake box?
anyhow undo your mod and see what happens

 

[WileyXB12X]

I let it sit on the tender overnight and it starts again, must have just drained it with it on for the TPS reset and multiple start attempts. Still won't idle, sputters and backfires in the throttle body.

I have the CIA air box cover, holes in the air box, and a catch can - all installed about 3000 miles ago with no problems until now.

Could bad engine timing be the cause of my problems?

 

[Macbuell]

I let it sit on the tender overnight and it starts again, must have just drained it with it on for the TPS reset and multiple start attempts.  Still won't idle, sputters and backfires in the throttle body.

That is not a fix for a bad ground... you should still look for a bad ground. LIsten to sparky-

Check & tighten the battery terminals. Do a load test on the battery, I believe output when running should be north of 12.4 vdc?

 

[sparky300]

look for a bad ground

Yep. Totally unrelated but I lost all my lights once... turns, cluster, headlights, when all 4 ground terminals broke at the ground screw under the lower triple. Check ALL your grounds

 

[WileyXB12X]

I hear what you're saying - do you think a faulty ground would cause all the other problems I'm having (no idle, backfire in the throttle body, etc)?

 

[lawdog]

If the ecm is not getting the proper voltage then the bike will run horrible. Not enough power to properly measure sensors, control fuel injectors etc. So battery troubles can affect the engine.

I would definitely test the battery and charging system. Do a load test on the battery with key off. Run the bike and do a load test with the bike running. You may have a bad battery, bad ground, wire, connection, etc. Or bad component of the charging system.

 

[WileyXB12X]

Thanks. I'll start checking everything out tonight when I get home. Luckily I just had the fly screen off and I checked those wires, they're good, so that leaves the rest of the bike to check out.

I do remember a little gouge in the rear spark plug cable coming off the coil where it looked like it had been rubbing through. Hmmm...

I can't do the load test with the bike running on account of I can't get it to run.

 

[WileyXB12X]

I went out and checked all the wires and grounds. I couldn't find anything obvious, nothing looks corroded or cracked other than the spark plug cable, but it wasn't worn through the sheath. The batter tested just shy of 12V after sitting on the tender.

I fired it up and got it warmed up by holding the throttle, it popped and backfired like a sonofabitch, I did that for about five minutes then let go - and it kept running. It held the idle at 1000 rpms for a few minutes, then spiked up to 2000 rpms and sat there for a few minutes, then sputted and died.

It started right up again so I figured what the hell and took it around the block a couple times. It was fairly smooth in the lower rpms for a while but any time I goosed it the engine would lag and start popping again and any time I came to a stop I kept on the throttle a bit to keep it from dying on me.

Improvement, I guess, but I have no idea why since I didn't really do anything to it. Still not reliable. I have an appointment at the mechanic this weekend, so I still have time to troubleshoot and cancel if we figure it out.


Thanks again for everybody who's taken a moment to give me advice and ideas to chase down.

 

[Mope]

Just another idea to troubleshoot - I ride with a guy who had almost identical issues a couple years ago to what you're describing.....ran with gas only and would sputter/die without, poor fueling causing smoke from TB, bucks like crazy if ridden while keeping on the throttle.

Spent 3 or 4 weekends trying to find the culprit. I suspected a electrical/ground issue because of the behavior and how common grounding issues are on our bikes. Finally, plopped in my extra ECM (same BIN) and she ran like a champ....which was better than finding something wrong in the harness. He had fried his ECM somehow. May not be worth buying a new one, but if you've got someone close with the same(ish) year you can confirm with TunerPro (or ECMSpy Mono if you bought that) if you have the same ECM and try it. Might solve the problem.....

 

[WileyXB12X]

Anybody in the Baltimore area with a 06 Uly ECM they'd be willing to swap for a check? HA!

 

[WileyXB12X]

Bike has been in the shop for a week now - they don't know what's wrong with it either.

 

[WileyXB12X]

So far, everybody was right.

Found an intake leak and replaced the gasket, a little better after that, but not perfect.

ECM was separated internally, but no visible crack on the outside. Replaced that and it would idle fine until it got warm.

Finally started throwing a TPS code, so they checked that and it was malfunctioning too. Replacing TPS now - we'll see if it's 100% after that. Their Buell specialist has been completely smitten with this puzzler.

 

[steve92106]

I'll be hoping you find a relatively minor (read: "cheap") solution to your problems as they sound an awful lot like mine. Hey maybe Buell built all these bikes with a planned lifespan so they'd all go to pieces at the same time and we'd all have to buy new replacements. Reading all these posts about poor idles, backfiring, surging, etc. sure doesn't make me feel good.

Had my bike serviced at 20k miles by the local HD dealer. Two weeks later I checked the oil level and it was below the dipstick! Filled it up and it hasn't budged since.

Resolved not to use the HD dealer so I had the forks overhauled by a SD area independent recommended by American Sportbike. The forks are fine but now I have a ding in my brake rotor that pulses when I brake hard.

Resolved not to use that independent. Now this!

 

[DrogeN Omen]

i had all those symptoms on my 2007 XB12SS last year. turned out a faulty wiring harness fried all my electrics, ecm, air intake sensor, tps sensor, battery.

I replaced them all and got an EBR ECM for $305 pre-tuned for a Drummer SS, runs like a champ now. have a flat spot at 5,500rpm in 4th & 5th gear but think its cause i have a custom built exhaust and its not fully straight through like the Drummer SS so om not getting enough flow.

suggest checking your ECM, air intake sensor, tps sensor and looking over your entire wiring harness for any fried wires, rubbing or cracks.

 

[WileyXB12X]

Got it back from the dealership yesterday after 4 weeks in the shop. They replaced the manifold gasket, TPS, ECM and one spark plug cable.

I still don't feel like it's 100%. It lets out a kind of "PUH" noise intermittently when cruising and when it's warm the RPM's tend to fluctuate at idle, but it starts, runs and stays running so I can go back to riding and commuting.