| Author | Message | ||
     Captain_awesome |
I have an 07 xB12ss that I've been having issues with since I bought her. I'm the third owner, and when I bought it, it had about 4k miles on it. Last year, I swapped the subframe for a ulysses (love the aesthetic) and everything was good for a while... I'm not sure where the problem is, but the bike will run fine, then after a few minutes and a lean, start hiccuping. When I say hiccup, I mean it won't keep a stable rev, it jumps, then drops, eventually turning off the engine. It starts right back up, runs fine for a second, then repeats its issues When I plug in bueltooth and do a live listen, it says cylinder 1 running lean... I clear the codes, and it runs find for a few minutes, then starts back up. If I unplug the bike from the battery for a few days, it forgets its problems for a while--but then it starts back up. I've read this board extensively over the past few months, and my guess from others is that the VR is burning up systems on its way out-- one of those systems is the ECU. Again, just my guess. The bike has been in a local Harley custom shop (the fellow use to own buells and likes 'em) but he can't figure out what's wrong, and we haven't started throwing money at it yet. So, what do ya'll think? | ||
| Skipbarberman |
Definitely have a lean condition, not sure what the 'VR' is.... Could be a fuel pump issue - either ground (lean, meaning movement?) or once the pump heats up it dies. Just a thought, need a bit more to go on. | ||
| Akbuell |
Various thoughts, in no particular order. If VR is voltage regulator, connect a multimeter to the battery terminals, tape it to the air box cover, and cruise for a bit. If the voltage spikes, then the VR is suspect. BTW, you have confirmed the battery cable(s) connectors are clean and tight, correct? Both ends? Since cornering seems to 'cause' the issue, pull the airbox and base and carefully trace the wiring to the front injector. Look for chaffed insulation; pull/push every connector you come to and confirm proper connection. Cogged/dirty injector? Ensure all of the fuses and relays are firm in their sockets. Carefully inspect the area where the wiring harness plugs into to ECM. And is the seat pan pressing on the wiring harness above those plugs? Most auto parts store loan special tools. Try finding a fuel pressure kit, and check. May involve a test ride like the VR check if running for a few minutes while sitting still does not prove helpful. In fact, try leaning the bike from side to side and bouncing the front end with the brake on and see what happens. Hope this helps, Dave | ||
| Skipbarberman |
Wow. Now THAT'S some great guidance there.... | ||
| Xb9sxvtwin |
BWB seems to have a heckuva lotta knowledge & experience on it. | ||
| Akbuell |
In fact, my step one would be to remove/install the ignition relay 5-6 times. Should remove any light corrosion, if there is any. Prior to the last install, put a light coating of dieletric (bulb grease) on the relay prongs. Start the bike, and see if the problem persists. If so, do the same thing to one of the other relays, and swap them one for the other. If the problem goes away, the ignition relay is most likely in a pre-fail mode, and needs to be replaced. Hope this helps, Dave | ||
| Captain_awesome |
I want to start by saying thanks for all the suggestions. We (shop and I) tried to start it up today and it just wouldn't turn over. Checked the fuel pressure--over 50 lbs. Connections seem good. They pulled the spark plugs and they were dry. So they are guessing fuel regulators. Hooked bueltooth to it and its showing throttle position short to battery. Thanks again for the information. I'll keep you guys updated | ||
| Akbuell |
Excellent progress. Might do to confirm the fuel pressure can be maintained at that level. A compromised TPS will probably send corrupted, or no, information to the ECM. I believe the ECM will not be 'telling' the injectors to cycle, causing the dry plugs. What follows is a general outline, as I have an '08 wiring diagram, so it may differ from your machine. The TPS has 3 wires, one signal (voltage) in, one signal out, and ground. The TPS itself is just a rheostat, so using your multimeter, connect to the signal in and signal out, and smoothly open and close the throttle. The ohms reading should smoothly change. Gaps or spikes indicate a bad TPS. As mentioned before, carefully inspect the wiring harness between the TPS and the ECM. Look for chaffed wires, sharp bends, or overly tight tie wraps. I have had that happen before. And don't forget, Garbage In Garbage Out, so if the input signal to the TPS is bad, or the TPS ground is poor, there will continue to be issues. Hope this helps, Dave | ||
| Captain_awesome |
Dave, I appreciate all the info. Hilariously, I thought your signoff was personal... "How does he know my name..?" I thought. Checked the pressure again, it seems fine, but we can't get the bike to start. They said its an ignition module or ecu After plugging in diagnostics, every time the bike gets turned on, the temp spikes and the fan kicks on. It won't hold codes, and so far as they know, nothing else is loose and no other sensors are bad. Maybe as a side note, they replaced the map sensor, and tightened all the loose wires they could find. I asked about the TPS, and they say its fine. Being that they don't have any buell ecus sitting around, it looks like I'll have to order one. I was thinking of an ebr racing programmable ecu, rather than an ebay ecu. Iirc, the 08 and later ecu is reprogrammable. Should ii get one of those instead of an 07? Thoughts? (Message edited by Captain awesome on May 17, 2021) | ||
| Ducbsa |
The OEM: https://idspd.com/xcart/products-buell/xb12 | ||
| Captain_awesome |
Ducbsa: If I'm going to pay 300 for an OEM ECU, shouldn't I spend the extra few bucks for an EBR ECU? Also, Thanks for the link! | ||
| 34nineteen |
Maybe as a side note, they replaced the map sensor I dont think a 2007 Ss has a MAP sensor. | ||
| Griffmeister |
IDS is THE source for replacement ECU’s. They have done the research and testing, just tell them what set-up you have. Before buying any parts I think the first purchase should be an electrical service manual for that year. The problems you describe could easily be an open or short in one circuit which a new ECU won’t fix. As a side note, the 07 and earlier ECU’s use a 16 pin connector, the 08 and newer are 32 pin connectors so they are not interchangeable. I’d start with the basics, use the wiring diagram and check the harness for every circuit that interacts with the ECU. Since you mentioned it, I’d disconnect the VR, the engine can still run on the battery in case there’s a charging problem. Work slow, take lots of notes and don’t throw random parts at it. Good luck. | ||
| Josequinones |
Before you do anything else, remove the bank angle sensor and see if it starts. I just went thru something similar, the bike was acting funny, and yesterday it would not even turn over, I cycled the kill switch and it would try to start but not finish. So this afternoon I disconnected the bank angle sensor (BAS) and the bike started like normal but showed a check engine light. Just to to double check I plugged the BAS and again the bike would not turn over. So I disconnected the BAS again and used ECM droid to mask the BAS from tripping the check engine light. Worth a shot. | ||
| Josequinones |
BTW, the BAS is below the rear seat, above and to the left of the seat latch. Unbolt it, unplug it and see if it starts. | ||
| Akbuell |
Capt a - You are very welcome. Hopefully, some of my info helped eliminate various things as sources of your problem(s). Jose's info is very interesting. Never considered the BAS. Certainly easy enough to check. Hope that is the issue, Dave | ||
| 34nineteen |
I thought the BAS only affected the fuel pump, not the starter. from the service book: GENERAL The Bank Angle Sensor (BAS), located under the seat, provides input to the ECM on vehicle lean angle. If vehicle lean angle exceeds predetermined bank angle limit, the Bank Angle Sensor will shut off power to the ignition and fuel pump. However, its a great diagnosing tip if you have a bike that is acting weird.  (Message edited by 34nineteen on May 21, 2021) | ||
| Captain_awesome |
Going to check out the BAS-- I know it was having an issue for a minute, largely because I didn't put it back in the exact angle it was when I did the tail swap. It has since been reanchored (instead of velcroed) to the floor of the tail section. I'm leaning hard towards dead short... When you try and turn the bike on, the fan kicks on and just runs, like the battery was put in backwards (don't ask me how I know). But, when you press down on the chassis, the fan cuts off. Something has connection, or intermittent connection, or a ground, or a short... I've spent the last week watching videos on finding shorts on youtube and I have a friend that might be able to help me trace the wires-- Hardware engineer for the win. Again, I want to thank you guys for the help so far. Its very appreciated. | ||
| Mlink |
I know it sounds too simple. Swap the battery. If there isn't enough amps the ECM gets false readings. | ||
| Firemanjim |
Yup, get a voltmeter on battery-- and by not start --what do you mean? Won't turn over? Turns over but won't fire?? And these bikes do NOT have a MAP sensor. Are they using ECM_Spy to look for codes? If not, get a copy and a cable to actually see what is in your ecu before throwing money at it. | ||
| Captain_awesome |
Got a new battery, still won't crank. Put a voltmeter on the battery, looks good. I changed out the relays, just in case. Won't crank. Disconnected the bank angle sensor. Won't crank. Disabled the BAS in buelltooth/ecmdroid. Won't crank. It has the new ECU from intelligent designs, so I don't think that is the problem. Any more suggestions? Firemanjim: When I say won't start, I mean, no clicking, won't turn over, won't fire, etc. I've used ECMdroid to test the coils-- everything clicks. When you say, "Whats in your ECU" what do you mean? I've got ECM spy, a cable, and a laptop I use to play around with. I also have ECMdroid and buelltooth. What am I looking for? (Message edited by Captain Awesome on October 25, 2021) | ||
| Littlebuggles |
Check the clutch safety switch, under the left bar at the clutch perch. If your bike is equipped with a sidestand safety switch check and consider bypassing it. I prefer mine active, it saves me when I’m about to do dumb stuff. | ||
| Captain_awesome |
Littlebuggles: Dude, I'm an idiot. This entire time, I havn't been holding down the clutch to try and start the bike. So, that is what I did today. It started up, ran for a second then died. It got me thinking about timing-- right? So I ran a TPS reset on the bike (been sitting for a year now, new ECU, etc...) Started right up. Adjusted the timing, let it warm up, adjusted the timing. Now, it sounds great! So, back to my original problem. Once the bike gets warmed up it starts misfiring. The code it use to give is "rear cylinder too lean". It would rev a bunch, backfire a few times, then cut itself off. It only happens when you let the clutch go. Pulling in the clutch causes it to idle just fine. A tech at Saint Paul said it was a timing assy sensor, so that is the next thing on the chopping block, assuming ya'll don't have any other thoughts. Wish me luck, it looks like I've gotta drill out some rivets. | ||
| Skipbarberman |
Go slow, light pressure with a sharp drill. | ||
| Captain_awesome |
Ok, drilled out the rivets, replaced the timing assy sensor, did a TPS reset... did another TPS reset... did a third TPS reset. Yeah, I got this. Runs like a champ now. Now the brake light and blinkers don't work. haha. yay. But it runs, and to be honest, that was what I wanted. Thanks for all the help guys, I appreciate it! I tried unplugging and plugging in the blinker relay. Fixed. The tail light was plugged in backwards. Fixed. Ok, gonna ride it a bunch tomorrow. if you see a xb12 on the side of the road, stop an say hi. (Message edited by Captain Awesome on October 26, 2021) | ||
| Littlebuggles |
Awesome, glad you found it. Fuses first for the tail light, then check the wiring harness for unplugged junctions and pinched wires, should be pretty quick while the seat is off. Always start simple, then work from there - a good buddy who was a mechanic has frequently reminded me of that over the years. |
