Intermittent very short loss of power with CEL then is perfectly fine

[Dawagner]

Hey guys,
I'm trying to figure out an issue I'm having with my bike. It's a 2006 xb12ss has the following mods(in case it helps): hawk exhaust, air box dremeled to open up air flow, KN Air filter, breather re-route, race mapped stock ECM. Randomly while driving it will loose power like it skipped a spark and then it will throw the CEL for a second and then go away and ride perfectly fine for the rest of the ride.

It's not every ride either, yesterday morning it was fine on the way to work, then on the ride home it had the issue. I then took it for a long ride on the evening and nothing at all was perfectly fine. This morning it happened on the way into work and then on the way home it was fine.

There are no codes stored when checked with ECM spy. I thought it was maybe some phantom issue from me telling the ecm to ignore the active exhaust valve (hawk exhaust installed) but I re-installed the servo and unchecked the box to reactivate it and still have seen the issue.

I've read about possible grounding issues so I removed cleaned and reinstalled the two frame rail grounds under the seat as well as the battery connectors. Checked the spark plugs and their wires to the coil, checked the following other connectors: tps, fuel pump, Ecm connectors, #77 connector and found nothing wierd or loose so I cleaned and reconnected them all. I saw a triple tree ground point mentioned in a thread but could not locate one on my bike. The fan still works as it should kicking in when the engine reaches specified temp. No fuses blown that I have found.

So I'm kinda out of ideas on what else to check or what it may be. My only thoughts now are the ECM itself, O2 sensor, or engine temp sensor. What do you guys think? Anyone else have these similar symptoms and find somethings? I'm ready to just trade it in if I can't get it figured out.

Thanks!

 

[Dawagner]

Any suggestions? I changed the spark plugs hoping it was maybe just a bad plug. But the issue persists.

I ran a code diagnostic and this last time the exhaust valve actuator threw up a code. Which is kind of odd as I have thw actuator still attached, just removed the cable as i have a hawk exhaust. Can the system tell if there is no load on the actuator? Was thinking about upgrading to a race ECM as maybe my ecm is on its way out??

Any suggestions would be much appreciated. Thank you,

 

[Chicknstripn]

I doubt the issue is your ECM.
I'm thinking your AIT sensor or O2 sensor.
I'm not sure how to test for either of those but suggest looking into how to test for a fault in those sensors before buying new parts.
You could also have a frayed fuel pump wire that is causing the fuel pump to cut out intermittently. Checking for that takes time, to pull the pump, but won't cost you anything but time. Does the pump prime normally?
Also, if you don't have a service manual go to www.buellmods.com and download one. You should be able to find test procedures for a faulty AIT and O2 sensor their.
Sounds like you're doing a real good job researching before attempting fixes. Keep that trend up.

Here's a pic of the grounds at the front triple tree.
http://www.badweatherbikers.com/buell/messages/142838/373336.html?1215183163
My 2007 xb12r had them located there. I swapped to a 2005/6 wire harness to modify my headlight set up and the 2005/6 harness does not have the same ground location. The ones pictures are in the tail section on my 2005/6 harness.

 

[Dawagner]

Thank you. Ill check those sensors out. I did check the external wires of the fuel pump and found nothing wrong but it seems that most of those fraying issues from the threads I've seen are on the inside and require pulling the pump. There havent been any priming issues and never has hiccupped while running the diagnostics on it. Might just suck it up and pull it to verify though as you say it only costs time.

I did look for the triple tree grounds but i think with that picture I will pull the headlight assembly out for due diligence to check again.

Thanks for the response! I'll let you know what i find,

Oh and do you mean the IAT (air intake temp) sensor?

 

[Chicknstripn]

Yeah
IAT. I get a little dyslexic from time to time.
Definitely check out the service manual. A TON of good info and directions in that bad boy!
If the manual doesn't have test procedures for those sensor start google searching for ways others Buellers have test them. Some Buell enthusiasts are pretty crafty when comes to trouble shooting and DIY fixes.
Good luck