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FIXED!!! Buell XB9S problem! Mystery O2 sensor fault!

Joined
May 31, 2008
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Location
Fort Worth
First Name
Dennis
2003 one owner XB9S with factory race kit (opened up intake and airbox/filter mods, race ECM, and factory race tuned (open) ehaust.

Overfilled the oil... 30 mile ride... started missing and died... no restart... new plugs... removed overfilled oil... no start... reset tps... trouble code rear injector open or short... trouble shoot from ecm forward and back... all checked out... only assumption bad factory race ecm!

Plugged in stock ecm... reset tps... started and ran. Again apparent race ecm failure.

Ordered new race ecm from Erik Buell Racing... install... set tps... started and ran but a little rough... engine light came on during test ride... ECM spy read trouble code 13 O2 sensor always lean... exhaust smells rich... reset trouble code... out for test ride... engine light on again... repeat 4 times (I am either a slow learner or I was giving the ecm time to learn on rides...) Finally give up to eat.

Halfway through supper get great idea to plug in "broken" Buell race ecm to read and save the maps... hit starter and the darn thing started! Reset tps and adjusted idle... idle and ran smoother than Erik Buell Racing ecm... thought maybe fixed. Took for test ride... again engine light on... trouble code 13 O2 sensor always lean... apparently the original buell race ecm was not broken!!!

SO........ O2 sensor screwy and in failure?

Ideas????????
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

My Buell blew an exhaust system flapper valve fuse that cause engine light activation and rough running.
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

My Buell blew an exhaust system flapper valve fuse that cause engine light activation and rough running.

If you are talking about the active valve in the muffler, not in my case. I have a factory race exhaust and the 2003 XB9S did not have the active exhaust valve. Is yours an XB12 or the newer model with the rotax motor? I knew the XB12 had them and am ignorant about the Rotax motor models.

Thanks for the input though!
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

still got my money on ignitor box. if it is not sparking good it will not be burning good and you get a lean code. also get smell of raw gas in exhaust.
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

Check your intake seals. If you have an intake leak it will cause it to run lean and throw codes. Start the bike, take a can of carb cleaner and while its running spray it from between the cylinders onto the intake where it connects to the head. If the idle changes then you found your problem. Intake seals are a known problem on older buells and there are many threads concerning them, the causes, and the fixes, on badweatherbikers.

Make sure to have the airbox on the bike when you do the test because any of the carb cleaner that gets into the intake tract will change the idle and will give you a false reading if it goes into the aircleaner side.

Also, as i mentioned before the tps sensor is prone to failure and will give bad running. If you recheck the tps setting after you set it and it is off then you know its bad.
 
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Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

Check your intake seals. If you have an intake leak it will cause it to run lean and throw codes. Start the bike, take a can of carb cleaner and while its running spray it from between the cylinders onto the intake where it connects to the head. If the idle changes then you found your problem. Intake seals are a known problem on older buells and there are many threads concerning them, the causes, and the fixes, on badweatherbikers.

Make sure to have the airbox on the bike when you do the test because any of the carb cleaner that gets into the intake tract will change the idle and will give you a false reading if it goes into the aircleaner side.

Also, as i mentioned before the tps sensor is prone to failure and will give bad running. If you recheck the tps setting after you set it and it is off then you know its bad.

During the test rides I would pull in my garage and plug into the port with ECM spy to read the fault. It was always the O2 sensor fault and the TPS reading were consistent. I will give the intake seal test this weekend. I think I have seen somewhere this done with a propane torch (unlit of course). Bad idea? Poor way? Your thoughts?
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

During the test rides I would pull in my garage and plug into the port with ECM spy to read the fault. It was always the O2 sensor fault and the TPS reading were consistent. I will give the intake seal test this weekend. I think I have seen somewhere this done with a propane torch (unlit of course). Bad idea? Poor way? Your thoughts?

I guess you can do it with an unlit propane torch but i have always done it with the carb cleaner since you have the small spray tube on it you can get into the tight spots. Plus a can of carb cleaner is $1.50-$3.00 and you can always use whatever is left to clean parts with.

It may be the O2 sensor but i like to start with the basics first since a seemingly unrelated problem, like intake seal leaks, could cause a different fault code. And the fact that the seals are a fairly common problem on buells. You dont have to be stingy with the spray either. Spray a good ammount of it on the intake to head area and make sure to spray from both sides.

Glad to see your learning and making good use of the EcmSpy program. Much cheaper than taking it to the dealer, who doesnt want to work on it anyways, and paying to have the codes read.
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

Well, since I bought a replacement Race ECM from Erik Buell Racing I wrote them for help. We just began the exchange and they have nothing but bad things to say about ECMSpy software. Saying they have HEARD of just setting the TPS causing the ECM Spy software to make changes in the ECM programming POSSIBLY causing the O2 sensor fault.

I tried to be clear my only want and need of ECM Spy was to be able to reset the TPS and read fault codes without resorting to the flashing engine light like doing the Morse Code thing. I also shot back to them the question could a weak ignition coil cause incomplete fuel burn and the O2sensor to throw that code... AND could an intake leak cause too much air for the O2 sensor and that cause it to throw that code?

I just sent my questions.
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

Well, since I bought a replacement Race ECM from Erik Buell Racing I wrote them for help. We just began the exchange and they have nothing but bad things to say about ECMSpy software. Saying they have HEARD of just setting the TPS causing the ECM Spy software to make changes in the ECM programming POSSIBLY causing the O2 sensor fault.

I tried to be clear my only want and need of ECM Spy was to be able to reset the TPS and read fault codes without resorting to the flashing engine light like doing the Morse Code thing. I also shot back to them the question could a weak ignition coil cause incomplete fuel burn and the O2sensor to throw that code... AND could an intake leak cause too much air for the O2 sensor and that cause it to throw that code?

I just sent my questions.

I havent heard of anything bad from the EcmSpy software like that. The only thing i have heard is as stated in the other thread, to save a copy of the current map to your comp. when you first plug it in to ensure that if you change any values on purpose or accidentally you can go back and upload the unmolested map if need be.

It doesnt surprise me that Eric Buell Racing wouldnt like it. I doubt they have ever used the software and probly consider it hacker stuff since its not licensed through them and they arent making any royalties off of it... Btw the EcmSpy software was created by a team of German software engineers who found a niche market for it since your ONLY option prior to that was either the race ecm, which gave you a generic one size fits all map, or stock. There is COUNTLESS hours(probly in the multi-thousands) of time spent creating and perfecting this software. I have personally used it many times as well as hundreds of others and ive never heard of the problems they describe.
 
Re: Buell XB9S problem NOT fixed! Mystery O2 sensor fault!

Good luck. Perhaps it was said before but hve you verified all ground leads/lugs/terminals? FWIF, my mechanic[cars] has repaired many wierd problems by finding/fixing a bad ground. remember, the ecu looks for very specific readings thst a POOR ground could cause. Also inspect all terminals/solder connections on both end of the ecu wiring. my .02, hope this helps. YMMV
 
PROBLEM FIXED!!!!!!!!!!!!!!!! Long story to follow!!!!!!!!!!!

Well… the problem was apparently the ignition coil on my 2003 Buell XB9S (with factory race kit)!

I think I gave too much credit to the Electronic Control Module (ECM) to know exactly what it THINKS the problem was, or REPORTS the problem as. Originally over filled with oil and thought I blew oil into the intake fouling spark plugs causing the bike to miss and die. Then not restart.

Back to my shop, fresh plugs, started and ran for one minute and died! Figured out how to CORRECTLY read fault codes and the indication was short or open to rear injector. (Please keep in mind there is one 02 sensor on the headers and it is the one off the rear cylinder, as this is a clue!) Check for broken/shorted wires between ECM and injectors, no problems. Checked injectors, no problem found. Only logical thought, ECM failed! If the wires are good and the injectors are good… that only leaves the ECM.

So bought a new ECM from Erik Buell Racing (EBR), switched out with the “bad” one, reset the Throttle Position Sensor (TPS) and the bike started. BUT smelled to be running rich. Out for test ride, fault light came on, back to shop, read the code, O2 Sensor always lean. I gave up for the day and purchased a new O2 sensor and as a “why the heck not” I also bought an ignition coil.

Curiosity got the best of me… so… I read the EBR Race ECM map and saved it, popped in the “broken” ECM and read the map and saved it. I wanted to compare the maps to see if they were identical (they were). Just to try and make my self more frustrated I hit the starter to listen to it NOT START… and the crazy thing started with no fault light!!!!! Now I was speechless! I took it for a spin and 2 blocks later a fault code. Back to shop and read code… same O2 fault always lean. Back out, idled no fault… 2 blocks later O2 fault code. AND one more time out to see the same fault… I guess because I am a slow learner!!!!! Kick dog… yell at wife… wait for purchased parts to arrive.

Parts arrive I look at the parts… look at the bike… look at the parts… look at the bike… see ignition coil is the easiest thing to replace… so since it was over 100 degrees and no air conditioning in the shop… replace coil. Start bike… no fault code… get set to take on test ride expecting 2 blocks later to turn around with fault code, I set out. MUCH TO MY PLEASURE AND SURPRISE… no fault code!!!!!!!!!!!!!!!!!! …of any type!!!!!!!!!!!!! The bike runs like a top (no, it did not spin around and fall over!)

So, here is what I think. ECMs on XB series Buells are STUPID! Yep… they see a problem make changes that cause another problems to be reported (or falsely reported) all the time lying to the tech about what the problem really is!

My logic. (Stay with me here!) The coil got hot and failed (or just failed with heat not being a factor. Texas is hot in the summer!) one cylinder cut out (wild guess rear cylinder) then a bit later the other cylinder cut out. The coil being the problem. Tried to start bike, major smell of fuel, one of both injectors obviously working but no spark to run. For that short time the front cylinder ran (speculation) after the coil failed to fire the rear spark plug… the ECM started trying to make mapping adjustment to make the bike run from the sensor input. The rear cylinder is injecting fuel but not igniting, ONLY the REAR CYLINDER is sampled by the O2 sensor, so the ECM tried to stop the injector from giving too much fuel (running rich) and shut down the rear injector entirely! The front cylinder next failed to have spark from the bad coil… engine died. Between the bad coil and the bad corrective action by the ECM… the fault code sent was rear injector short or open since the ECM shut it totally off (speculation on my part).

So, the coil cooled during the 30 mile trailer ride home, started and got warm and failed again, the ECM still thought it was the injector because I had no way to clear the fault codes. I knew I needed to reset the TPS when I got a replacement ECM. I bought a ECM Spy cable and received the software. Now I had to wait for the replacement ECM. The ignition coil had LOTS of time to cool, so when I plugged in the new ECM, and reset the TPS the bike started and ran. BUT it was throwing a weak spark. At idle it was strong enough to do a complete fuel burn (or enough where the O2 sensor read within “normal” range) so no fault code. HOWEVER… at higher RPM the spark was too weak and there was incomplete fuel burn… the O2 sensor was reading unburned fuel in the REAR exhaust and telling the injectors to run leaner, therefore throwing the “always lean” fault code! As it was telling the injectors to be “always lean” compared to the mapping!

Anyway… speculating the ECM had limited programming to comprehensively read and evaluate the sensor input, it tries to adjust what it controls to make the engine run so the O2 sensor gets the reading it needs to be within “normal”. BUT by doing so reports what it has done giving a stupid human like me the impression the darn thing knows what it is talking about! Therefore taking the fault code literally!!!!

So… there ya go. The ignition coil, replaced the bike runs perfect with no fault codes. I now have a spare (expensive) EBR Race ECM and a spare O2 sensor.

The moral of the story… do not take the fault codes literally! They report only what they are programmed to report AND NOT the reason they are reporting that fault. The ECM constantly works to change output, from the input and may report what it had to do make (or try and make) the engine run.
 
Didn't do the Buell Blasts have the same silly issue and using a hair dryer to heat up the coil would create the effect of riding, etc. and thus you could test in your garage!? Sounds like you should keep some spare coils on hand! :rider:
 
Didn't do the Buell Blasts have the same silly issue and using a hair dryer to heat up the coil would create the effect of riding, etc. and thus you could test in your garage!? Sounds like you should keep some spare coils on hand! :rider:

To the OP. Glad you got it fixed man!! :thumb:Hard to diagnose and fix a intermintent problem like that. Im curious as to why the ECM didnt read a bad coil if you checked it when the coil was hot and malfunctioning. When you test components it will send voltage to that particular part your testing and will read voltage, etc... Pretty similar to testing resistance the old fashioned way with a voltmeter. Your right that you shouldnt rely to much on the bike to self diagnose itself and sometimes oldschool is best :clap:

To Tazman2, I havent seen an issue with the coils on any of the buells really. For the most part they are solid bikes. The blast had a problem with the automatic choke they used on them. It would malfunction and usually make the bike run really rich causing it to either not start or start and foul plugs within a few miles. In fact even when they worked correctly the choke would stay on so long that having spare plugs on hand was a necessity. :doh:
 
My mistake it was the ignition module on the Blast. Buddy had one a few years ago and I googled the problem for him then and apparently was a common issue on them. Ahh well. Fixed problems are always good! :rider:
 
My mistake it was the ignition module on the Blast. Buddy had one a few years ago and I googled the problem for him then and apparently was a common issue on them. Ahh well. Fixed problems are always good! :rider:

Yeah, H-D's have had a problem with the ignition module on the Evolution engines(including the sporty + blast) for a long time. They finally designed a better part for the Twin Cams.
 
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