| Author |
Message |
    
Wackyracer
| | Posted on Wednesday, September 19, 2007 - 10:17 pm: | 
|
I just picked up a 2003 Buell XB9R with a running issue. The bike has 6800 miles on it and has the Buell race kit installed. The bike is very clean and in excellent shape otherwise. Once I got the bike home (ran very rough, misfiring and sputtering) I took off the Corbin seat and noticed that the steel rail on the bottom of the seat had rubbed through the red rubber on the positive battery cable. The steel rail bolts to the subframe. I repaired the cable and put the stock seat back on. The previous owner had also been running VP U4 race fuel in it (leaded) and this is what was causing the engine light to come on. It was sending the o2 sensor code so I replaced the sensor with a new one and drained the fuel & replaced with 93 octane pump gas. It's no longer posting any codes but is now running even worse. I've checked the coil resistance, plug wire resistance and condition, replaced plugs, injector volts & resistance, leaky injectors, battery voltage, and all are within spec. I've gone through the wiring looking for other possible shorts. The bike will start every time and run fine at first for maybe 5 seconds. Then the front cylinder will start misfiring. When I pull the front plug it's still wet with gas. The rear cylinder will continue to fire for however long but looking at the plugs I would say that both cylinders are running very rich. If I blip the throttle the front cylinder will kick in again and then revert to misfiring again (whether I let the revs down or try to keep them up). It misfires all through the rev range and gets worse the warmer the engine gets. If anyone out there has had a similar problem and might be able to point me in the right direction I would certainly appreciate it. These bikes are more complex than one would think even if you do have the factory service manual. I don't have the diagnostic equipment that the dealer has and after calling a few service departments in my area I don't think I want to take the bike to any of them.
Thanks! |
Sparky
| | Posted on Wednesday, September 19, 2007 - 11:58 pm: |
|
It's probably something simple but elusive to find. Your description sounds like some kind of intermittent ignition failure.
Possibly the coil is breaking down or the ignition ground from the cam position sensor is getting corrupted. If you had a way to observe the high voltage spark like with an oscilloscope or a timing light connected to the spark plug cables, that might give a clue as to the health of the spark delivery. |
Al_lighton
| | Posted on Thursday, September 20, 2007 - 01:04 am: |
|
Corbin has a "voluntary recall" on that seat mounting method. Contact them and they'll get you brackets that don't short to your battery.
It's possible that your AFV is very high, which combined with the warm up fuel scalar, is making the bike run so rich that it's fouling the plugs. The O2 sensor is critical in setting the AFV, and if the O2 sensor had been ruined by leaded fuel, it could have skewed the AFV badly.
If you had VDSTS, you could read the AFV, and if it is off, reset the AFV to 100. But without, all you can hope to do is clear the plug, start it, and DRIVE AWAY IMMEDIATELY and get it up to highway speed under heavy load until it is fully warmed up, then drop back to steady state cruise to re-learn the AFV, hoping that is doesn't foul the plug out first. If you start it and let it idle, even briefly, it will foul the plug again.
OR not, just a thought.
AL |
Wackyracer
| | Posted on Thursday, September 20, 2007 - 11:53 am: |
|
Thanks for the responses guys. I have checked the coil and it's within spec according to the manual. I've also used a spark tester and both plugs appear to be getting a healthy continual spark. The exhaust smells VERY rich and the front plug appears to be fouling from way too much gas. I've tried running the bike at a steady speed to learn the new fuel value and nothing has worked so far. The front cylinder will fire once in a while when first started but it will always revert to a constant misfire. Once warm it is almost impossible to get the front cylinder to fire no matter what you do with the throttle. I will check the cam sensor wiring again, it certainly wouldn't hurt to double check. I have been putting in new plugs with every change to make sure that a fouled plug doesn't mask a fix. I'm starting to think that I need to get the VDSTS and the Breakout Box so I can diagnose this problem. I am hoping that someone else out there has had the same symptoms and knows what needs to be fixed. In the meantime I'll keep searching. If I do find the problem I'll post it. |
Sparky
| | Posted on Thursday, September 20, 2007 - 04:27 pm: |
|
Another thing to do is clean the IAT Intake Air Sensor inside the airbox with alcohol or carb cleaner. This thing is very close to the crank vent hoses and can be coated with oil and gunk. Some have reported better driveability after cleaning it.
When was the last time tha air filter was cleaned/replaced? |
Wackyracer
| | Posted on Thursday, September 20, 2007 - 05:41 pm: |
|
It has a K&N air filter which I cleaned and re-oiled when I got the bike even though it didn't appear dirty at all. The IAT sensor appears to be very clean but I'll try the alcohol anyway. This isn't just a driveability problem though, this bike is unrideable with it's present condition. I've been at the office all day so I'll try a few of the suggestions when I get home this evening. Thinking about the extremely rich problem though, could an injector still be bad even it's reading the correct resistance? Just a thought. |
Wackyracer
| | Posted on Friday, September 21, 2007 - 11:27 am: |
|
I've read on another post that if you disconnect the battery for 24 hours, the AFV will automatically reset. Has anyone else heard of this, or is it false information? |
Wackyracer
| | Posted on Saturday, September 22, 2007 - 08:13 pm: |
|
Well I tried to reset the AFV by disconnecting both battery terminals for 24 hours. I don't know if it did or didn't but it hasn't changed a thing in he way it runs. I also found a couple of wires in the bundle right in front of the belt pulley on the motor that had rubbed through to bare wire. I repaired all of them and used zip ties to configure them away from the areas they were rubbing on. I've looked everywhere I can possibly see to try to find any possible shorts. The bike continues to run the same way. Fire it up and it sounds great for the first few seconds. Then it's right back to firing on one cylinder. Blip the throttle and the front cylinder starts to fire again. Hold the throttle open at a steady throttle setting and it will soon be running on the rear cylinder only again. Let it back down to idle and it will ALWAYS revert to running on the rear cylinder only. I've removed the injectors and hooked them back up outside of the throttle body and spun the motor with the injectors squirting in a bucket. Both injectors seem to have a nice fan and the amount and pattern appear to be identical. One note though: the service manual states that each injector should read 12.25 ohms across the terminals. Mine read 12.70 for one and 12.80 for the other. Are these too far out of spec? Most other parts have a range that the ohms need to be between, but the book states that it needs to read 12.25 ohms, and if they don't then replace them. Problem is I've switched the injectors around and the problem stays with the front cylinder. Plus the rear cylinder ALWAYS fires, no matter what. I've checked the spark by clamping both spark plugs to the ground cable on the top of the frame and spinning the motor with the starter and both sparks appear to be healthy. WHAT GIVES! I wonder how the driveability would be affected by pushing the bike off a cliff? Has anyone heard of this new technique? Please advise. |
Buell920
| | Posted on Saturday, September 22, 2007 - 10:47 pm: |
|
here is a little FYI that may help
in you ignition system you have your spark plug, fuel injectors and your cam sensor. the bike takes the info from the cam sensor and determines the position of the piston. from that the injectors will fire at a give point and the spark plugs will fire at a predetermined point after. ((( the injectors and spark plugs will fire at the exact same time from each other no mater what. even when people advance and retard there timing to try and correct the PING the duration from the injector fire to the spark plug fire is constant ))) if the rear cyl is firing and is able to keep the bike running in any manor and the fuel pressure is good, and the injectors are spitting gas, you need to trace bake from the plug to the ECM. if the bike has codes take it to the shop and have them do nothing other than pull them and go from there. \
tests to try
1) swap plug wires F/R & R/F and see what happens
2) swap plug wires at the coil and see what happens again F/R & R/F
p.s buy a service manual and electric manual worth there weight in gold.
SC |
Wackyracer
| | Posted on Sunday, September 23, 2007 - 10:55 am: |
|
I do have the service manual and I have been doing all of the troubleshooting I can do without a breakout box and VDSTS. I did have one code when I originally picked up the bike. It was the code for the O2 sensor (previous owner was running leaded race gas). I replaced the O2 sensor with a new one from American Sport Bike (and the gas) and haven't gotten a fault code since. I've checked the resistance of the plug wires and I've switched them around (I have new one's coming from American Sport Bike on Tuesday but I don't think it'll change a thing based on the wire switch). I've replaced the plugs with new ones at least 6 times now to rule out a fouled plug with each fix I try. I do think that there are many things that can be ruled out because it's only happening to one cylinder, and no matter what I change it stays with the front cylinder. I've checked the coil and it's within spec, although I'm starting to wonder if it quickly jumps in and out of spec when the bike is running? Is that possible for it to fire for the first few seconds, stop firing & then start again when I blip the throttle? Whatever it is, it's elusive and I absolutely can't stand the possibility of taking it to any of the service departments in my area after talking to them on the phone. I'm convinced that I'm better qualified without the diagnostic equipment that they have (maybe they have it?) because at least I have a functioning brain (they didn't seem to have one of those). It's a frustrating situation to be in. |
Wackyracer
| | Posted on Sunday, September 23, 2007 - 06:50 pm: |
|
I've pulled the spark plugs once again and both are completely black and the front was wet as well (I pulled them right away after running it for a short period of time. I'm sure that the mixture is quite rich when the motor is run for a short time (which is all I've done lately)). But I began to wonder if the spark plugs that I've been using would be considered correct for an XB9R with a race kit at sea level. I'm using NGK DCPR7E's that I found were the stock HD plug equivalents. Should I be using a different heat range plug? Could my ECU be bad, causing the bike to run intermittent? Could the initial problem with the seat grounding the battery have done anything to the ECU? I wish I had the stock one to throw in and check. This is driving me nuts because everything I check seems fine. I did find a few possible shorts and I repaired them all. Please don't hesitate to post if you have any ideas. It gives me something to do besides stare at the bike and ponder my next move. |
Sparky
| | Posted on Monday, September 24, 2007 - 12:13 am: |
|
If you've never had the TPS checked, now would be a good time to do it. If it is out of cal, it could be trying to enrichen things up when it thinks it is stoic.
Do you think that the previous owner might have changed the fuel mapping in that ECM? Perhaps if you have a friend that can let you borrow a good ECM temporarily, that would help eliminate one cause.
There is a test for the fuel injectors in the throttle body part of section 4, pg 4-115 that appears to be a leak test. One turns on the key for 2 sec then off for 2 sec and repeats the above for 5 times. If there is any fuel in the intake manifold, replace the injectors. Did you do this when you had the injectors out?
One more thought. Have you checked the condition of the intake manifold seals and injector O-rings? |
Wackyracer
| | Posted on Monday, September 24, 2007 - 09:28 am: |
|
Hey Sparky, I did do the leak test for the injectors both in and when I had them out. The bike was running fine for the previous owner (and good friend)until recently and the reason he decided to sell it to me because he has no mechanical aptitude. So I'm quite certain that the TPS hasn't been messed with. The o-rings are in great shape and used new motor oil on them as the manual states to avoid tearing them. I'm going to replace the plug wires tomorrow when they come in the mail from American Sport Bike. I don't think it's going to change anything though. I'm going to have to find an ECM so that I can rule that out. Also, I can't really do the intake manifold test because there would be no way to tell that it's running worse, it's already running on only one cylinder! |
Wackyracer
| | Posted on Monday, September 24, 2007 - 11:47 pm: |
|
I just stopped by my friend's house that sold me the bike. I spoke with him a little more about the bikes history. He owns 8 bikes now including a Buell Lightning X-1 (2000). He said that he runs race fuel in both bikes and has for a long time. He's never had a problem with the X-1 and the Firebolt never had a problem until he fitted the Corbin seat. Is it possible that the short that the Corbin seat had created to the positive cable on the battery may have done any damage to the ECM? According to the seller the problem surfaced soon after fitting that seat. Has anyone else had this problem? |
Wackyracer
| | Posted on Sunday, September 30, 2007 - 10:50 am: |
|
I finally got another ECM (stock) to try and see if the bike would run on both cylinders. I installed the ECM and put everything back together. I started the bike and it actually ran on both cylinders! It ran rough so I took it for a "learning" ride and just a couple minutes down the road it started to smooth out and would accept full throttle (wouldn't when first installed). It's still rough (missing & sputtering) at certain partial throttle settings and steady throttle. Does this sound like something that a TPS reset would solve? |
Sparky
| | Posted on Monday, October 01, 2007 - 01:35 am: |
|
A TPS reset calibration should be done because the "new" ECM doesn't know the zero point of your TPS sensor until the procedure is done. But, more to the point, it sounds like you may have found the root cause of your initial problem with the seat shorting out the ECM.
I'm not quite sure what the mechanism for the ECM fault would be because the +12 VDC power comes in on one pin of the two ECM connectors. But with the seat shorting out battery power intermittently, the damage could be due to heavy current transients overpowering input filter circuitry and possibly any internal sensor input circuits.
It would be interesting to hear what Corbin has to say regarding the consequences of Buell owners buying their seats resulting in damaged electronics if this is a wide$pread $ituation. |
Wackyracer
| | Posted on Monday, October 01, 2007 - 10:37 am: |
|
Then I guess my next question is whether or not the stock ECM can be used with the Buell race pipe and K&N filter? Will it run too lean even though it has the ability to learn or do I need to find a good race ECM and then get the TPS reset done? |
Heyfred
| | Posted on Monday, October 01, 2007 - 11:02 am: |
|
Stock ECM can be used with the Buell race pipe and K&N filter?
Yes, ran with stock ecm for several years with K/N and race muffler.
(Message edited by Heyfred on October 01, 2007) |
Wackyracer
| | Posted on Monday, October 01, 2007 - 11:34 am: |
|
Heyfred, did you run a race ECM on the same bike as well? If so, are there any major differences? |
Heyfred
| | Posted on Monday, October 01, 2007 - 11:57 am: |
|
did you run a race ECM on the same bike as well? If so, are there any major differences?
Same bike.
Differences, no pinging. |
|
Troubleshooting (Poor Starting/Running/Handling/Ride Issues) »
Archive through October 31, 2007 »
'03 XB9R - Misfires on the front cylinder...