| Author |
Message |
    
Skully
| | Posted on Monday, February 13, 2006 - 06:35 pm: | 
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Hey BadWeB,
I need your help once again.
Bike set up: 2003 XB9S with 25,000 miles, stock engine, perforated air box, K&N filter, D&D muffler, PCIII, and the wide band O2 sensor. I wrote the map based on some dyno testing done previously but checked the map using a wide band exhaust gas analyzer.
On a ride in December, I noticed a slight miss or hesitation around 3500 RPM at a constant speed. As I continued to ride the bike to work over the next week or so, the misfire got worse (broader RPM range). I decided that it had to be the intake manifold seals even though spraying carburetor cleaner around the seals made no difference on how the engine idled. So I replaced the intake seals with the blue James Gaskets seals without any improvement in the misfire.
I then installed new NGK spark plugs with absolutely no difference. I used my Technoresearch VDSTS and checked everything that it will check (fuel pump, coils, injectors) and everything checked out fine. The Buell ECM does not display any trouble codes either.
Using the repair manual, I checked both the air temperature sensor and the engine temperature sensor. Both show the correct resistance at room temperature and both vary resistance as a function of increasing temperature. I used a heat gun to increase temperature.
The misfire now shows up at idle (rear cylinder header is cooler to the touch than the front inferring that the rear cylinder is dropping out) and extends up to approximately 5000 RPM. Going to full throttle at any RPM makes it stop misfiring.
I loaded a zero map and the problem does not change.
Any ideas?
Thanks,
Keith |
Buellin_ri
| | Posted on Monday, February 13, 2006 - 07:52 pm: |
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Have you checked your plug wires for any sign of rubbing/arcing. I had issues with mine. There was an updated design, its a cheap place to start. |
Skully
| | Posted on Monday, February 13, 2006 - 10:19 pm: |
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Hey Zeke,
Thanks for the response. I have a set on order along with a new coil. Keep your fingers crossed...
Keith |
Buellin_ri
| | Posted on Tuesday, February 14, 2006 - 04:51 pm: |
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Good Luck! |
Skully
| | Posted on Sunday, February 26, 2006 - 07:19 pm: |
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As of today, I have replaced the intake manifold seals, replaced spark plugs twice, replaced the spark plug wires, replaced the coil, installed the stock O2 sensor, removed the PCIII, and finally, installed the stock ECM. The bike is still misfiring on the rear cylinder. What’s left?
Thanks,
Keith |
Henrik
| | Posted on Sunday, February 26, 2006 - 07:29 pm: |
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Just a WAG, but how about a partially clogged injector? Or maybe faulty an intermittent wiring fault wrt. the injectors?
Henrik |
Charlieboy6649
| | Posted on Monday, February 27, 2006 - 01:25 pm: |
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My wife's bike misfires (hiccups) as well. Can't figure it out for the life of me. Done it for a long time now... |
Skully
| | Posted on Monday, February 27, 2006 - 01:35 pm: |
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This is more than a misfire; the bike runs on the front cylinder mostly unless it is at full or nearly full throttle! |
Skully
| | Posted on Monday, February 27, 2006 - 01:36 pm: |
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This is more than a hiccup; the bike runs on the front cylinder mostly unless it is at full or nearly full throttle! |
Blake
| | Posted on Monday, February 27, 2006 - 10:37 pm: |
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Maybe your bike has A.D.D.?  |
Skully
| | Posted on Tuesday, March 07, 2006 - 01:45 pm: |
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SUCCESS!!! Finally, I got down to the last item in the ignition/fuel injection systems: the rear injector.
Replaced it last night and found it was dirty. Don't know why as I believe that I am very careful to not let any dirt get in and I assume there is a fuel filter.
At any rate, it is not a difficult job and the engine does not have to be rotated. I plan to post more soon but wanted to let everyone know what the results are.
Keith |
Blake
| | Posted on Tuesday, March 07, 2006 - 02:38 pm: |
|
Keith,
Maybe check around the air filter seating/sealing surfaces for signs of a leak there somewhere?
Or... you didn't leave a rag in there did you?
If we live to be 100, I'll still be teasing you about that.  |
Skully
| | Posted on Tuesday, March 07, 2006 - 06:33 pm: |
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All of the intake manifold surfaces and the throttle butterfly were relatively clean.
Bring it on! I can alway tease you about the multitude of failures you have every time we go on a trip!  |
Road_thing
| | Posted on Tuesday, March 07, 2006 - 06:57 pm: |
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Pretty good guess, Henrik...
 |
Blake
| | Posted on Tuesday, March 07, 2006 - 07:24 pm: |
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Me? Have a failure? What you talking 'bout? |
Blake
| | Posted on Tuesday, March 07, 2006 - 07:26 pm: |
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I did fail to stay on the bike that one time. |
Henrik
| | Posted on Tuesday, March 07, 2006 - 10:31 pm: |
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Hey, thanks r.t. - and I haven't even fully embraced the whole fuel injection thing yet 
... and those are some awfully large bottles with quite low fluid levels ...
Henrik |
Blake
| | Posted on Wednesday, March 08, 2006 - 12:11 am: |
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If Keith wanted to really tell on me, I'd be in big trouble. We've been through some interesting experiences together. Sturgis '98 comes to mind among many others.
Ask Keith about the killer Hill Country deer if you ever get a chance. |
Skully
| | Posted on Wednesday, March 08, 2006 - 08:22 am: |
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Yep Henrick was on the right track. If I had thought about it, I could have eliminated the sensors including the O2 sensor and ignition timing. They would have affected more than just the rear cylinder.
And it seems there has been some kind of drama on every trip I've been on with Blake. The Fall trip to Arkansas was almost boring without him. 
I can you for sure, the bike does not run as good as it did with the PCIII installed. I'm holding off putting it back on in hopes of having a Direct Link map installed in my stock ECM negating the need for the PCIII.
Keith |
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XB9 Engine Misfire