Stuttering and dying

[shortymac83]

Ok, 03 xb9r, no mods whatsoever, 13,xxx miles.

The bike will randomly crap out on me. If I'm at speed, it'll dramatically lose power, buck and jerk, and generally act like it's trying to die for about a mile, upon which time it'll wake up and be fine.

If I'm coming to a stop, it'll stumble until I try to open the throttle to take off, where it'll completely die. It'll start (hard) and then is fine after that.

I've done a tps reset, and it doesn't matter the temp, humidity, time of day, whatever, it still wants to crap out. However, it's totally random. I can ride it all week and be fine, but take it out the next day and it dies twice.

No codes, no funky idiot lights. Where do I go from here?

 

[user_deleted]

in all likelihood your random shut-down is caused by either electrical....loss of ignition....loss of fuel. i would start by checking the 5 known things on a 12 year old XB that usually cause such a problem:
1-the ignition switch and it's wiring plug
2-your side-stand safety interlock switch(stock on 2003 models)
3-the harness and plug at lower left rear of frame/tank that feeds your in-frame fuel pump
4-your plugs where they attach to your ecm unit....and the unit itself in the plug area for any signs of cracking.
5-your battery cables where they attach to the terminals and in particular the negative cable where it attaches to the frame lug. MUST be clean....tight....no signs whatsoever of looseness.

 

[Chicknstripn]

Lunatic knows his stuff! Follow his advice.
If you still can't find any issues; I'd bet either your battery needs to be replaced or you have a fuel pump wire grounding out inside your tank/frame.
Good luck

 

[user_deleted]

thanks stripn.....always appreciate your very kind words. regards, john

 

[shortymac83]

Alright, checked all the plugs I could find, and they looked clean and crack free...discovered a breather had broken off...and also, what's that vacuum port on the throttle body, and where does it go to? I didn't see any spare vacuum lines...

 

[rchuff]

Just put a plug over it.

 

[Chicknstripn]

Like rchuff said, just put a cap on it or plug over it. That nipple/vacuum port is for an emissions canister that comes on the CA model bikes.
How is your trouble shooting going?
Bike running any better?

 

[shortymac83]

Bike is still doing its thing...I haven't discovered any bad connections yet. It's weird in that it starts fine, but will only act up after warming up a bit. It idles ok, but then chokes when you hit the throttle, or when the throttle is open. Sometimes, even when it accelerates ok, under consistent throttle, you can feel surging. Leads me to believe it's a fuel problem, but I'm not sure what it would be.

 

[Chicknstripn]

Can you give us a list of the things you have checked?
Will help us try to give you some direction as to what you need to trouble shoot next.
BTW I think your right. I too think you might have something wrong in your fuel delivery system. Does your fuel pump prime normally?
Start researching old threads that have the same symptoms. Google search Buellxb and then add whatever symptoms you're trying to learn more about.
Good luck and keep us posted.

 

[shortymac83]

Things checked using the chassis service manual:

1. Neutral switch
2. Clutch switch
3. Fuel pump harness
4. Spark plug wires
5. Battery cables

Today, I pulled the kickstand switch and bypassed it. It had oil on it and appeared to have had oil suck its way up into the plug a bit - bad connection? Anyway, took care of that... We'll see how it does when I go to work tomorrow and will update you.

 

[Chicknstripn]

Where is your bike leaking oil from to have it saturate that plug?
Just curious.

 

[shortymac83]

It was leaking from the shifter and, way earlier, from the front rocker cover. The shifter shaft soaked the whole side of the bike eventually. It lost its gasket. Got that problem solved months ago and haven't done much more than a hose and wipe down of the bike. The plug is kinda hidden

 

[Chicknstripn]

Ok. I get it. Just making sure you didn't have a base gasket issue.
Thanks for clearing that up

 

[shortymac83]

Welp, that didn't fix it...

Riding to work (12.5 miles away), I start out with a few stop lights, then about 3 miles of a 35 mph speed limit (so, 40 mph). After that, it speeds up to 60, with a stop after a total of about 8 miles. After that, another mile, a stop, then a couple miles to finish it out.

I was going, and it was running well, no bucking, no misfiring, nothing. Fine at all the stop lights in town, no issues on acceleration. I thought I had solved the problem. Then I get to the stop sign in the middle of nowhere, after a constant speed for 8 miles. It idled down, and was idling OK when stopped, but as soon as I tried to hit the gas, it stuttered and crapped out on me. Wasn't immediate, but it'd stutter, rev a bit, stutter, rev a bit, die. Almost like when a car runs out of gas. Put it in neutral and fired it up on the second hit of the starter and it was fine for the rest of the trip. Maybe I had two issues? It does seem to run markedly better, although I'll have to do a longer ride to ascertain that...

 

[Chicknstripn]

Sounds like you might have a loose fuelpump wire inside your frame/tank.
Start looking into the fuelpump rebuild thread. Might be worth your time just to pull the pump and replace the fuel filter and screen anyway.

 

[shortymac83]

This is getting old. Pulled the fuel pump, everything was right and I didn't see any chafing. I'll tighten up the plugs, but is there anything else to check while I have it out?

 

[Tbone]

Check for any DTC's, even though there is no CEL it still might be generating some info?

 

[Chris standen]

I've had similar problems with my xb9r for years, nobody seems to know what the problem is. Changed various sensors, tps and reset, fuel pressure check (set up gauge to check when using the bike), no fault codes, renewed battery, leads, took off alarm, disconnected lean angle and side stand sensors. The bike misbehaves after about five mins. I want to change the Ecm but find they're not that easy to get any more. Does anyone have a good standard one or a race one?

 

[shortymac83]

Btt, I swapped out the camshaft position sensor...no change. Before I swap the ecm, any other suggestions?

 

[Mags11]

Quick simple ground check

Yes, I had strange electrical issues, and someone here suggested taking a jumper cable directly from battery ground to the engine head. This will work in the garage, but not sure the simplest way to attach a jumper wire somewhere directly to motor. This will for sure eliminate the battery negative to frame intermittent grounding issue and better point you in that direction.