| Author | Message | ||
     Kodas |
Just checked the shop manual. You are observing the "Intermission" only. 99x1 is correct. No trouble codes are present. As far as the ECM knows, your bike is fine. | ||
| Jayzen |
OK...so I guess I need to ask if anyone knows why my 99 X1 might be sputtering. It does this around 2500 to 3500 RPM even when I change the spark plugs. It only has 7700 miles on it. | ||
| Jayzen |
One of the other symptoms is that the plug in the front cylinder is always white and the rear is normal. Would that be an intake leak somewhere? WOuldn't the trouble codes indicate that? | ||
| Bomber |
Jay -- it does sound like an intake leak on the front cyclinder (from the data you've posted) . . . although your bike doesn't have a lot of miles, the gaskets used on the intake manifold are not made of unobtainium, and may have deteriorated over the last 4 years . . . . they are relatively easily replaced, after you check em by spraying with WD40 or your favorite spray testing solution (smile) . . .. . spraying around a suspect intake path gasket with the fluid will result in an RMP change (likely a drop) if the gasket has gone south as for trouble codes, I'll let someone with direct Buell FI experience answer that one | ||
| 99x1 |
An intake leak wouldn't show a trouble code. The O2 sensor is only used from about 2500 to 3500 RPM (IIRC, I will have to check this). What colour is your O2 sensor? I also seem to recall that the O2 sensor is mounted closer to the exhaust port on '99s, they don't last as long. Does it also sputter when cranked hard? (the O2 sensor is not used when the throttle is wide open) Also, check the ignition ground connection (under the tank left rear) - it can give similar symptoms. | ||
| Jayzen |
When I put the engine under load it runs smooth and clean. When I let off it starts popping when the RPM gets down to 3500. If I sit at a light and rev it will occasionally backfire. | ||
| 99x1 |
Sounds like the O2 sensor - they normally cycle up and down in voltage (cross counts) in closed loop mode, and as they age or get contaminated they slow down their response (slow cross count) - this will make it surge or hesitate if it responds too slow. Check the grounding of the sensor to the exhaust pipe (tends to rust), as well as the colour / condition of the vented portion inside the exhaust pipe. When mine went bad, I noticed it first on freeway ramps - it seemed difficult to maintain a smooth steady speed - then my fuel consumption started to go up. There are methods of testing the sensor (using a propane torch and a voltmeter), but it may be easier to swap it out. (cross reference a 1992 Chev pickup / AC-Delco AFS-20 / Bosch 12014). | ||
| 99x1 |
I just tested my old O2 sensor, and compared it to the new one. Although I never got any engine codes, it appears it is almost dead. The old one never gets above 0.027 volts (27.6 millivolt)when heated with a propane torch, and drops slowly. The new one goes to >0.8 volts and drops very rapidly back down. I tried running with a datalogger on the O2 sensor, but couldn't see any cross counts - it stayed pretty steady at 0.45-0.50 - seems different then what is seen in a car....   edited by 99X1 on July 17, 2003 | ||
| Sparky |
My Firebolt has started an intermittent erratic idle condition during which if I attempt to quickly open the throttle, the engine wants to die. This only happens after running hard like at the end of a freeway off ramp while waiting for the light to change. The idle will jump from its normal 1000 rpm and cycle between 1200 and 1500 for a few seconds, then return back to normal. While in that cycling stage is when the engine will (sometimes) die if I goose the throttle. The dealer checked it out last week and could only find that the TPS was just slightly off, so they readjusted it. They couldn't duplicate the condition I described so it seems like it will have to become obvious for them to fix it. The throttle response feels a little better now but the cycling occasionally comes and goes although it hasn't died yet. What components would be suspect? The bike has gone 12.8k miles flawlessly up to now. It has the factory race kit and is otherwise stock except for Torquemaster plugs. Sparky | ||
| Jayzen |
Thanks for that info on the O2 sensor. I will try this and also see if the front intake manifold has a leak. | ||
| Motoboy |
Ok, I'm more of a lurker but here's my latest problem. Took the 1999 S3T in to have valve guide seals replaced. The dealer did that fine but found out that after putting it back together it ran like crap. Indeed it does. I got it back from them because I need transportation at the moment but it obviously has something wrong. When at steady throttle it sputters and knocks, but under acceleration or deceleration it runs smoothly. What's wrong? Obviously some sensor, but could it be the TPS or the O2 sensor? FWIW the O2 sensor is a new one since the tech was having a hard time fixing the problem - and of course was never able to quite get it solved. I suppose I could take it to another dealer but does anyone have any guesses on where to start the diagnosis? The dealer was HD-Buell of Edison, NJ, and are a reputable dealer. Geoff | ||
| Anonymous |
Check to see that the injector wires are on the right injectors. (they are marked front and rear)Check for intake leak. Go back to the dealer and have them re-zeroed the TPS. Check to be sure that injector wires are not pinched in the rocker box covers. With the bike idling, wiggle the rear injector wires. Does it drop that cylinder? If so check that wiring at the injector plug. If the bike has an after market pipe and a stock ECM it will not run right no matter what you change. Get the race ECM if the pipe is not stock. And don't listen to Blake or the ten other people when they tell you it is the side stand switch. | ||
| Blake |
Hey! I think I was just slammed by an anony. Where are all the anony bashers to stick up for me?   Anony bashers please read the above and hushup. | ||
| Kodas |
Motoboy, what do you mean by sputters and knocks? Is the bike suffering a pre-ignition knock at idle (unlikely)and not during acceleration? How was the bike running before the guide seal replacement? Some wild guesses (in addition to Anonymous's which are a very good start 'cept for the aftermarket exhaust, I have 'em and my S3T runs fine!): Weak or broken valve springs, incorrect valve timing, damaged, incorrect seated intake or exhaust valve. Just mentioning since dealer worked in this area. Check the front & rear plug wires are attached to the proper coil connectors. Its suprising a bike would even run like this but sometimes it will. Sounds Trival but loose connection of the battery cables or coil can cause the bike to run poorly. A clogged tank vent valve or pinched tube will also cause grief. Don't forget the Intake Air Temp & Engine Temp sensors could be malfunctioning or have a bad connection. Don't let the dealer off the hook! Have 'em call the factory and get the thing fixed!!! I too doubt its the side stand switch  hey. hey. edited by kodas on July 23, 2003 | ||
| Motoboy |
Just to follow up on some of your questions, it is a completely stock bike and ran fine before I brought it in. It only sputters and knocks under steady throttle, not during acceleration and not during idle. It idles a bit high, maybe 1150rpm. Tech said so but was at a loss. He could spend tens of hours trying to find out why, costing me big bucks. Looks like I'll have to take it somewhere anyways. Geoff | ||
| Motoboy |
Even more follow up. After riding this morning, I found that the throttle position of partly open, maybe 1/4 open, is when it sputters. More open and it is normal, all the way shut is normal. You know, maybe it is the TPS then, I would ASSUME that the Buell tech reset it but then you know what that gets us. I'll call today and ask if he did. Geoff | ||
| Kodas |
Hope it is the TPS. This is a good hunch but the tech should drawn and quartered if it wasn't done! As far as costing you anything, a responsible shop won't charge for fixing a problem they've caused. Speak with the head of the garage and make this clear. Find out the experience level of the person (certified Buell?) who worked on your bike and ask for a better trained one if necessary. Having had this experience, waiting several weeks and the bike failing the day after the 'fix'. I found the tech was fresh from Buell school and mine one of his first 'projects'. A more experienced person was called in and the problem real problem dealt within the hour. I'm still curious about the sputter and knocks under steady throttle. A knock to me means a ping: pre-ignition or detonation. That along with the high idle suggests the timing is too far advanced. But the'knock' would normally occur during acceleration. Why the timing would be off is a mystery as I wouldn't have thought the techs would go anywhere near the cam position sensor to work on the valves. So consider this a long shot. | ||
| Motoboy |
More update: after having a chance to ride the S3T about 110 miles this evening, I've learned that it only does it's little trick between 2,500 and 3,500 rpm. The Buell tech at the dealer said he reset the TPS. But, they had the bike two weeks trying to figure this out. Obviously it is some sort of sensor problem, the bike runs fine above 3,500 rpm and actually runs fine below 2,500 rpm but I don't have it there long. Closed throttle is fine, too. Even though they replaced the O2 sensor is there any chance that this problem is still the O2 sensor? Cam sensor sounds like a culprit, too, but again, the bike runs fine outside of that one range. Ah, the pleasures of Buell ownership! Geoff | ||
| Kodas |
Motoboy, this does sound like a problem with closed loop operation which kicks in from 2500-3500 rpm. The 02 sensor is used from 2500-3500. 99X1 has some recent posts about the 02 sensor operation (cool pics of butane torch, too). Sounds like Jayzen was having a similar problem and the issue was discussed July 16-17 (which hasn't rolled off current web page we are on). The vote from the past Jayzen discussion was the O2 sensor or an intake leak on the front cylinder. The unusually high idle may just be the fast idle needs to be adjusted, which is likely if the dealer had the injector assembly removed. Its unlikely the CPS was messed with for a valve job. | ||
| Cartman |
99x1, could you tell me how exactly you tested your O2 sensor with a propane torch? Thanks. | ||
| 99x1 |
"...how exactly you tested your O2 sensor.." See O2 testing. The sensor has to be heated to >600 degs F before it will read, and the oxygen in propane makes it read very rich (>0.8 volts). Put the positive lead of your meter on the O2 lead, and the negative lead to the body (ground) of the sensor. As they age they get slower to react, so a new one will drop the voltage down rapidly once the flame is removed. The sensor is difficult to test on the bike, as you have to be above 2500 RPM (the rear cylinder doesn't fire often enough to keep the sensor above 600 degs at idle), and the ECM sends a bias voltage (0.45-0.50 volts) until it senses the O2 sensor varying the voltage. Even with a digital storage scope triggered off the tach pulse, I'm having a hard time trying to capture the O2 data. edited by 99x1 on July 26, 2003 | ||
| Cartman |
Where do you read the voltage from and what do you use as your powersource? | ||
| 99x1 |
"Where do you read the voltage from and what do you use as your powersource?" The O2 sensor is like a battery, it generates a voltage on its own: <0.5 volts for a lean condition, >0.5 volts for a rich condition. Just connect one voltmeter lead to the O2 wire and the other meter lead to the O2 metal housing. Heat with a propane torch, and read the voltage - which should be >0.8 volts. | ||
| Awprior |
I just picked up a Mikuni HSR42 carb. I was wondering what if any mods may need to be done to the jets right off. I have an open K&N airfilter and a full D&D exhaust. It doesn't look like it should be hard at all to install, just I haven't done a ton of work with jetting yet. Any help would be appreciated. Thanks. | ||
| Doncasto |
Alex: Mikuni's website has a pretty decent tuning guide at: http://www.mikuni.com/fs-tuning_guide.html They have done some updating on their website (http://www.mikuni.com/fs-carburetor.html) and it now looks like it is a very good source of information of getting your HSR42 to run correctly. The best tuning, IMHO, is always done via a dyno - but using the website info you should be able to get things close. I have found the Mikuni to be much more sensitive to changes in temperature and altitude than the CV. You may want to find a source for jets, needles, etc. if you find the carb requires resetting several times a year as I do. Don | ||
| Kaudette |
Hello there. For those XB enthusiasts out there, I have a question regarding a flat spot in the acceleration that I haven't been able to fix yet. At 2750rpm there is, 90% of the time, a flat spot where if the gas is not dosed exactly right (very smooth on the throttle) the motor just boggs down - this goes from ~2800 to 3000 - after 3000, no problem and the motor really takes off. There is no backfiring, or other detonation, just the motor stumbling and then taking off at 3G. The air filter is new (K&N), with an aftermarket exhaust (vance equivalent). I had the same issue with the stock pipe and filter so my guess is that it is not an issue with the aftermarket gear. I've tried multiple gas stations, running hot or cold, always the same deal. Any thoughts or solutions out there? (my next step is a dealer visit for the TPS & installation of the race ECM...) Thanks for any advice! | ||
| Sparky |
Did you remove the rubber snorkel out of the intake tract in the left side of the gas tank/frame? This may or may not alleviate the flat spot you're experiencing but it should allow more oomph in the mid to upper rpm range. BTW, this is one of the steps in installing the factory race kit. Your best bet though is installing the race ECM & recalibrating the TPS for it. That'll make the bike run slightly richer and hopefully better although it may not eliminate the flat spot. However if you want to completely get rid of the flat spot, the consensus of this board would probably say give Nallin Racing, a Badweb sponsor, a call. They've got all the right answers. Sparky | ||
| Jim_witt |
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| Kaudette |
Thanks for the tip - in effect I have the race ECM but haven't installed it yet as I've been breaking it in for the last 1000 kms. A quick note - the bike is an european model which has the "famous" white wire heading into the ECM (apparently in an attempt to restrict power / emissions for EU regulations). Any idea as to what this wiring does to the motor / injection, or potential ramifications for getting the cutter and electric tape out?  For the snorkel, I'll give it a try when I get the race ECM installed early September... | ||
| Suzypoozie |
I have a S1 Lightning and it's back firing. I moved to CO from Portland so I probably have to adjust the jets, but I don't know what size jets I would need for high altitude. I also have swapped out the air filter for a Forced Air (is that what it's called?) filter. Any suggestions for what I need to do to stop the bike from backfiring? |
