Missing and shutting down.

[Braunwalder]

Hallo everyone.

My 2007 xb 12 Lightning is stopping for no reason.
It started to miss a few weeks back when getting hot.
Now it shuts down, and won't start again until it has cooled off.
Fan is working correctly, and no fault codes present.
Have changed the fuel pump and filter.
The problem seems to get worse, but only happens when the engine is hot.

Hope someone has any ideas.

Cheers Paul

 

[Cooter]

A bad CPS does that.

 

[Braunwalder]

Thanks I'll try that.
But shouldn't the ecm log a fault code?

 

[Cooter]

Not necessarily. Your Buells FI tech was designed well more than 20 years ago, and was very rudimentary even back then.

Besides, all "codes", even today, were never meant for blindly replacing parts without any further diagnostics.

 

[rjames75]

ECM going bad?

 

[Braunwalder]

Sadly it seems to be impossible to get a new CPS for my model.
Someone sugested to try from an earlier model, but it not always works.
Would like to hear from anyone that has tried that.

 

[Barrett]

CPS tested? Doubt you need one.

 

[DieterVonCunth]

https://buellservice.com/en/shop/ulysess/elettrico-ulysess/pick-up-cod-722365/

 

[Braunwalder]

Any idea how to test the CPS ?

 

[Cooter]

If you wanna be a mechanic, you'll need this.

http://buellmods.com

:eagerness:

 

[34nineteen]

Can’t you just tell him? Why make him read through that big book?

 

[Cooter]

I could read it all and then type out all the same instructions for him, but he'd still have to read the ones I wrote? So why not get the info from the people that engineered the bike and bothered to write instructions on how to fix it, seems like a MUCH better choice to me. Let's see if he takes the path of self-help and empowering righteousness, or continues down the I-must-be-spoon-fed dark side.

No one needs to be a mechanic to read the service manual, they do know how to read. I think he'll be ok.

Theres always the pay-a-professional option, but what do I know:upset:

 

[Barrett]

Any idea how to test the CPS ?

Heat

Pulse signal to tach

Oscilloscope

 

[Cooter]

The last time I used an Oscilloscope was when Mr. Zimmerman was teaching electronics class in H.S. and we were building an AM radio from scratch. High Schools have changed 'a bit' since then but it helped me manipulate the big Sun diagnostic machine we had at Andy Granetellis Tune-Up Masters I ran in the 90's

Now they auction them as "Vintage"

https://www.mecum.com/lots/544681/

:crushed:

 

[34nineteen]

Weren’t you in my American History class back at Ridgemont HS back in ‘85?

 

[Cooter]

Thanks for the pizza

 

[Braunwalder]

Finally found the problem.
It was the ECM.
I cut it open and resoldered all the pins.
Thanks for all the help guys.
Went for a long ride today, and it never missed.

 

[Barrett]

Finally found the problem.
It was the ECM.
I cut it open and resoldered all the pins.
Thanks for all the help guys.
Went for a long ride today, and it never missed.

It was the ECM.

I am now seeing them fail at alarming rates. Own an XB for the long haul? Wise investment to have a spare on hand.

 

[Kurlon]

I assumed the ECUs were heavily potted, how much work was it to get down to the PCB as my 'spare' likely is going through a similar failure mode?

 

[Cooter]

I assumed the ECUs were heavily potted, how much work was it to get down to the PCB as my 'spare' likely is going through a similar failure mode?

They are dang near 'filled up' inside the box so it's a TON of work to try an at-home repair. Baking them helps, but you better have a bunch of free time to kill.

I have not seen any increase in ECM failures besides the usuals: DDFI-2 fuel pump circuit failure (before they added the relay, and it is a physical circuit burn that causes it, but IMO still not worth the time to un-pot it for repair), and of course the Uly low seat issue.

I keep a lot of DDFI-3 ECM's with OE Uly fuel maps handy. The early boxes are still easy to find but resellers are getting more aggressive with their pricing, using words like "classic" or even "vintage":concern: