08 Buell-does tach sweep while driving...

[dodge]

And sometimes just dies. No fault codes. Seems to be happening more frequently...any ideas what might be going on? Is this symptomatic of something going bad perhaps?

thanks!

 

[njloco]

Sounds like something is loosing contact for a split second then reconnecting, fuel pump relay ?

 

[dodge]

Yes, its just like turning off the ignition only more often than not, the engine just stutters briefly, then catches back on. Wish it would throw a code lol.

thanks

 

[casual_observer]

Is this symptomatic of something going bad perhaps?!

sounds perfectly normal. carry on.

 

[Cooter]

Check for corrosion in your ignition fuse/relay circuit in the fuse box (all the relays are the same so swapping them around is OK), including the red run switch.

Check all grounds near the steering neck, a known problem with Buells.

 

[rb70383]

Wiggle test while bike is running...

 

[Cooter]

Wiggle like this??

 

[rb70383]

One technique. This might work as well

https://youtu.be/Q4_3Jkrp0O8

 

[dodge]

Well, I thought I had the issue resolved when I found that the WB O2 sensor was not fully tightened. Weird...not problems until I filled up with gas. Was worse than ever sweeping several times within a few minutes while I drove away. Pulled and replaced all the fuses and relays. Hope that does it... Maybe the IG switch?

 

[dodge]

Wiggle test while bike is running...

This has me on the right track I think. Its something temp related as well. Early am..65f started up and when I did hard R/L turn it would do the sweep thing. Then when starting up at 80f and turning L/R no sweeping. Sounds like a connection-ground issue?

thanks!

 

[Cooter]

Hello? Is this thing on? A loose O2 sensor would not make the tach sweep or cause the bike to shut off.

But any of these things would:

Check for corrosion in your ignition fuse/relay circuit in the fuse box (all the relays are the same so swapping them around is OK), including the red run switch.

Check all grounds near the steering neck, a known problem with Buells.

Are your battery terminals tight? Take them off and check for corrosion there too.

 

[rchuff]

Check around your steering neck for broke wires or wiggle the wires at steering neck with bike running and see what happens.

 

[Barrett]

And sometimes just dies. No fault codes. Seems to be happening more frequently...any ideas what might be going on? Is this symptomatic of something going bad perhaps?

thanks!

Sir: this is the result of two possible culprits. ONE: frayed or completely torn and arcing main power feed to the frontal components, one of which is the instrument cluster. TWO: design flaw from the factory in the wiring harness for the ignition switch. you will need to split the main wiring harness in vicinity of the steering neck, identify the main power RED WIRE and trace it for crack/partial tear/break. lengthen the factory ignition switch wiring harness. it is approx. 15mm too short as installed. the result? a turn of the "handlebars" to either left or right full lock puts undue-stress on the harness-to-switch assembly connection causing intermittent loss of power to the switch assembly. your gauges then SWEEP because they are losing power. both of these problems were factory design faults not addressed till major 2008 upgrades appeared.

 

[mattyMaxMac]

I had the same thing > After the bike was hot, the tach would sweep and jump during riding. My bike would also turn off randomly.
I would wiggly the left harness to get the bike started again -

CAUSE- The ECM/Computer solder joints were cracked/broken - Very common on these Buells -I soldered mine been running like new!
SOLUTION- (1) New ECM (2) Carefully use a hacksaw and open the computer to solder joints(google) (3) message me and I can help you out

Took Me forever to figure this out. Thought is was a frayed wire, went as far as soldering new wiring into the ECM Plug

 

[mattyMaxMac]

I had the same thing, got worse with time > no codes > After the bike was hot, the tach would sweep and jump during riding. My bike would also turn off randomly.
I would wiggly the left harness to get the bike started again -

CAUSE- The ECM/Computer solder joints were cracked/broken - Very common on these Buells -I soldered mine been running like new!
SOLUTION- (1) New ECM (2) Carefully use a hacksaw and open the computer to solder joints(google) (3) message me and I can help you out

Took Me forever to figure this out. Thought is was a frayed wire, went as far as soldering new wiring into the ECM Plug

 

[Endopotential]

Matty, any pics or details about exact what part of the ECM needed to be re-soldered?

 

[mattyMaxMac]

https://www.ebay.com/itm/BUELL-ECM-COMPUTER-REPAIR-REPAIR-SERVICE-XB-XB9s-XB12s-FireBolt-Ulysses/233597484604?hash=item36637ebe3c:gMoAAOSwHDVeybh0

Second photo will show you what side to cut into> Make sure you go slowly when cutting into the sides so you don't cut into the motherboard> the top part you can use a razor blade to cut the seal(again do not go too deep). Add new solder to all pin joints, make sure to heat the old joints well, then add the new solder. Can uses Kwik Seal to seal the ECM

 

[EuropaChris]

I'll add my experience here FWIW since I've been chasing this issue on my '06 12Ss since 2011 on and off. Originally, it appeared to be fixed by applying some Dow Corning dielectric grease to the connector at the cluster. I went after the harness at the steer head on a wild goose chase - it was fine. The problem would go away for a while, sometimes even several years, before it would come back. Finally it became much worse and fooling with the connector and grease didn't help. Finally, while out riding I decided to pull over, pop the seat and simply unplug and reconnect the ECM plugs and check the grounds, relays, fuses, etc. I got going again and the problem was gone! OK, so that at least gave me a good clue.

I started searching for info again, and came across mattyMaxMac's post above and thought AHA!!! I wasted little time performing a cover-ectomy on the ECM, indeed finding some suspect solder joints under magnification, and re-soldering the connections. I let the Loctite non-corrosive clear RTV sealant cure 24 hrs. and was stoked to test it out. I fired it up and all was good....until I sat on the seat. As soon as I sat down the tach started it's seizure, but if I stood up, it stopped. I did this three times, same results. ??????!!!!!!????? WTF? (and no, I'm not that fat, just a wee bit fluffy). I've been soldering for 35+ years so I was pretty confident my repair work was OK and needed to look at the rest of the stuff under the seat.

First I went about cleaning and tightening the grounds. I was just about to reconnect the harness to the ECM when something caught my eye. It was a tiny spot on the underside of the bundle. I looked closer and saw shiny copper and pink wire insulation. DOH! The tach wire! I looked down in the frame and saw a similar bare copper spot on one of the ground wires that ran perpendicular under the harness Actually, it was several bare spots at different locations, all very small.

I'm pretty sure this has been the cause all along. Any time I'd futz under the seat (new battery, charging battery, checking wiring, etc.) I'd move the harness just enough so it would not ground out the tach. After a while it would either move back into it's old position or wear a new spot, which might have taken years. Eventually it would cause the tach to start freaking out again. I re-routed the ground and fixed up the harness and permanently solved the issue.

As a side benefit, the bike does seem to run a little better since the ECM rework, although I had no issue with it prior. She's been a reliable machine for 27K miles so far.

Chris

 

[buellonthecreek]

Ended up being a wire that separated inside the plastic sheathing. Shop sourced and repaired it. Not cheap.. All is well now.