| Author | Message | ||
     Brewster |
I have an S3 with a race kit ECM, race kit air cleaner, a stock header, and a Vance and Hines muffler. The bike runs great when idling or accelerating, but cannot hold a steady cruising speed without missing. It feels like a lean miss on a carbureted bike but is harder and longer. It misses at all speeds and RPM's until 85 MPH. The only thing in common is that the throttle is barely off of idle when cruising. It did the same thing with a Power Commander on it. Any suggestions are welcome> | ||
| Deltacruiser |
I'm not even close to an expert at this, but my guess would be that your TPS (throttle position sensor) is off. Try having your dealer reset the TPS. You have to take it to a dealer to have this done as far as I know. It takes them about 1/2 hour and $50.00 of your money to do this, but that may solve the problem. I had mine reset when I put the full race kit on my X1 and it made a huge difference in how it ran compared to pre-TPS reset. (I rode it about 30 miles to the dealer after installing the race kit to have the TPS reset. It ran, but not very smoothly.) Deltacruiser | ||
| Josh_ |
Check TPS, intake gaskets, injector O-rings, coil, sparkplug wires, plugs ... You might get the injectors cleaned while you have them off to check the o-rings if you can find a place that'll do it. | ||
| Al_lighton |
I suspect O2 sensor. It sounds like it is only doing it while operating in closed loop. It isn't throwing codes, though? O2 sensor is a wear item. Not too expensive, might be a reasonable thing to buy one, put it in, see if it improves the problem. If it doesn't, well, you'll have one for when you DO need one. Al | ||
| Brewster |
I just got the bike out of the shop from the race ECM installation. The TPS was set then. The intake seals are good. It has done this with two different O2 sensors, one for the Power Commander and one for the race ECM. No error codes show up. | ||
| José_quiñones |
Try cruising in a lower gear to see how it reacts. Cruise in 4th or even 3rd and see how it does. If it runs better at a higher throttle openings compared to the low throttle openings it sounds like the TPS is still not set correctly. When the TPS setting is off, it makes a bigger difference in the mix and you will notice it "surge" when the throttle is barely cracked compared to when you are 1/4 or even 1/2 way open where the air/fuel is going in much faster and it's harder to notice the "surging". | ||
| José_quiñones |
That being said, it could also be a leak at the intake gaskets or the injector o-rings as Josh mentioned. Buell updated the Fuel Injection intake manifold and intake gaskets after the 1999 model year. If you have never changed yours it would be a good idea to do it. The part #s are: Intake Manifold (Part Number 29532-99YA) Black viton intake manifold seals (Part No. 26995-86B), | ||
| Matty |
Brewster, I had the same issue on my S3. Replace the engine temp sensor. It usually won't throw a code, so it's darn near impossible to detect. Keep us updated. | ||
| Brewster |
These are all very good suggestions. I cannot get the bike into the shop for two weeks, but Matty's idea to replace the engine temp sensor is something I can do. Tomorrow I'll stop at the shop and hope they have one in stock. I will keep you informed. | ||
| Al_lighton |
Based on what you'd checked, I bet Chris is right. Al | ||
| Mbsween |
Brewster, I had the same experience as Matty on an X1. Mine would foul the plugs after it got really bad awhile. Its easy enough to fix and like chris said it doesn't normally post a code | ||
| Brewster |
I installed a new engine temp sensor yesterday. On a test ride it had the same miss, but not as bad or as often. Later after the sunset and cooler air temperature, it stopped missing. I may have more than one problem. I will keep you posted. | ||
| Brewster |
Tomorrow I will pick up and install a new air intake temp sensor. I need to eliminate everything I can to find this problem. | ||
| Sssss3girl |
OK, I've read everything on this site that I can find on DDFI, but I haven't found anything that really addressed my "issue". I don't know if I would call it a problem. I have a 99 S3 which is, of course, fuel injected. It has the race ECM, the Buell race exhaust, a Power Commander (with the 4-lead O2 sensor), and a Crossroads air intake and breather system. After I got all the hardware set up the way I wanted it, I had it Dyno'd last fall. Now it seems to run mostly great, but it still runs richer than I think it should. And the throttle response is also not what I think it should be. It seems to have a real lag when taking off from a stop...so the very bottom of the throttle has a dead spot, if that makes sense. My question is this...will I screw things up if I readjust the PC manually to lean it out? Do I dare experiment with this, or will I have to have it Dyno'd again? I've never had a fuel-injected bike before, so without needles and jets to adjust, I'm a little lost. Any help is greatly appreciated!! | ||
| Josh_ |
Why do you feel you need the PC? I'd remove that from the equation and put a stock (well, Bosch equiv) O2 sensor in and give the RaceECM some time to adjust. If it doesn't seem to be spot on, change the plugs (which might be fouled if it's too rich) and check the various sensors (IAT, head temp, TPS). If all else fails, get a TPS reset so you know the throttle position is at least accurate. | ||
| Sssss3girl |
The history on this bike is a bit odd...it was outfitted with everything I've mentioned, except that it had dual air intakes and dual throttle bodies on it. I ran incredibly lean then, and idled at 2000 rpm after cruising for 20 minutes. So I took it all back to stock, breadbox and all, except for the ECM, but it ran really rich. So I changed out the air intake and ran with it for a couple hundred miles...still really rich. Then someone told me that with these early fuel injection systems, you really need the PC. So I put it back in, along with the O2 sensor, and it leaned out some. That's when I put it on the dyno, and it's much leaner, and oil consumption is almost zero (it had been so rich it was washing the cylinders), but I think it's still richer than it should be. I will check the plugs, as well as checking with the dealer with regard to the TPS setting (I don't remember if they reset that or not). Thanks for the input! | ||
| 99x1 |
"... but I think it's still richer than it should be. " The FI bikes use the temperature sensors as an indication to richen - similar to putting on the choke on a carb (but increases the injector pulse time when the engine is cold). The '99s had the head temp sensor mounted near the rear spark plug, and it is very fragile - the wire easily breaks just inside the sensor. The resistance goes down with increasing temperature, so a poor connection looks like a cold engine. The sensor can be tested by measuring its resistance at room temperature (40K <-> 50K), stuck in ice water it should read ~135K, and in boiling water it should read ~2K ohms. The intake air sensor could also be defective (less likely), or the fuel pressure could be too high (the injector would be putting in more fuel then the ECM expects at the nominal ~50 psi). The AFV value was rumoured to be able to get too far out to come back in on early versions, but this was probably reset when they did the TPS? | ||
| Sssss3girl |
Aaaah, you may be on to something...that would explain why it doesn't stay consistently lean when cruising at a steady 4000. It tends to bounce around - leans out, then jumps back to rich for a while, then goes lean again...there's an A/F gauge that I get to watch, and it probably gives me too much to worry about. But I will definitely take a look at it. Thanks!! | ||
| Iamike |
Lucy, What restaraunt do you have? My parents live in Bloomington and I get up there once in awhile. We almost never eat at home when I'm visiting. I also have a '99 S3 | ||
| Sssss3girl |
Mike - It's a little coffee shop called Diamonds. It's at 1618 Central Ave NE...for sure stop in! If you see my Buell out front, just ask for me (I spend a lot of time in the basement, doing administrative stuff  ). Always up for a conversation about bikes! We can compare/contrast S3 issues... That'd be great! Hope to see you this summer sometime! | ||
| Brewster |
I finally got my S3 back from the dealer. They changed the Air-Fuel Value from 128% to 122% and put in a set of 10R12A plugs as per a Buell tech bulletin. It runs like a rocket...I find it hard to believe that small of a change makes such an improvement..I an happy! | ||
| Brewster |
Bad news! My S3 ran great for a week, then it went back to the same old problems. I pulled the injection system off and am in process of installing a recalibrated CV carb. | ||
| Sssss3girl |
Good news! Thanks to 99x1...I changed out the engine temp sensor, and the bike went from 33 mpg to 45 mpg after riding about 200 miles. So it obviously leaned itself out due to correct engine temp readings. Yeh!! Now I just have to get the throttle thing worked out, and I'm afraid I'll have to take it in for that. My mechanic told me that the TPS is easy to install, but it needs to be calibrated, and he's not convinced that's the problem. From everything I've been reading on this site, I think that's what it is, and I'm hoping he's not just trying to gouge me. Any suggestions on how to get around the calibration issue? Is there any way to do that myself? You guys rock! | ||
| Brewster |
I installed the CV carb and am using the race ECM only for ignition. It runs great! Bye Bye, fuel injection! | ||
| Ryker77 |
Brewster I'm going to start a new thread could you check it out. http://www.badweatherbikers.com/buell/messages/47623/124108.html?1119892124 |
