| Author | Message | ||
     Mke |
So I'm trying to troubleshoot my Uly's bad gas mileage. Spent a bit of time searching the archives for ideas, and am looking for input. Last fillup I got 90 miles before the fuel light came on. It's usually been in the 130 mile range, which I think is bad to begin with. It's a 2008 Ulysses with less than 5000 miles. Here's what I've checked/done thus far: Seafoam put in about 4 tanks ago. O2 output voltage at Idle (cold start) = .8V -.9V O2 output Voltage at Idle (warm engine) = .8V -.9V Blipped throttle and looked for O2 voltage changes...saw slight changes, but didn't see anything below .45 (not sure if I even should see the V change with minor rpm changes.???) TPS reset done Grounds cleaned and checked Ran a few miles without O2 sensor connected. = No Check Engine light. I haven't tried checking for intake leaks by spraying carb cleaner around the cylinder heads, but that may be my next step. I was thinking it's about time to get an ECMSpy cable and dig a little deeper, but any ideas would be greatly appreciated. | ||
| Tootal |
A 2008 with 5000 miles means it's been sitting a lot. I assume you used seafoam to clean the fuel injectors. Could be you got them clean and now they are shooting a lot more fuel. The bike should readjust but riding without the O2 sensor and not getting a check engine light is weird! With an 08 you might want Tunerpro instead of ECMSPY. The engine learns at a steady rpm over 3000. Hook up the O2 sensor and ride at a steady 3300-3500 for a while and see if it can relearn and get your fuel value back where it should be. Other than that I haven't a clue. An intake leak will cause a bad idle and other problems, I don't think it's that. | ||
| Arry |
"Last fillup I got 90 miles before the fuel light came on." This isn't a real good indication of bad mileage. Are you sure you started with a complete "fillup", or did you stop when the gas nozzle clicked off? During those 90 mile did you go for several short hops without fully warming the bike up? Also my fuel light seems to vary some as to when it comes on, so not an accurate measure of how much gas you've used. On the other hand you may actually have a problem. Sorry if this seems obvious. | ||
| Kag |
I have been getting right about 138miles before the low fuel light comes on. Any chance its an bad injector. You could pull the plugs and look to see if has signs of running super rich. | ||
| Mordueman |
On a long run at a steady 70-80 mph, I am getting 160 miles before the fuel light comes on, its a lot less around town | ||
| Ratbuell |
I'm in the 130 range for the light, too. When your mileage dropped, did you notice any performance change? Has it done it for more than a single tank? | ||
| Thejosh |
You need to post how many miles to how many gallons. Reset your odometer when you fill up and ride around, at next fillup, note how many gallons it took. It could be a faulty fuel light I guess? | ||
| Fltwistygirl |
Light on at 130 seems about right for us too although with the winter blend of petrol and short rides around town, it's way less. Disappointed during my last fill, in the 43 mpg range, but still waaaaaay better than the truck, and more fun too! The best mpgs for us on both Ulys have been in the spring/summer, up the interstate at a spirited clip. Second best is flogging these bikes in the twisties, also during the warmer months. FWIW the XT with the EBR ECM gets better mpgs than the X with its stock ECM. But, the XT also has more miles on the odometer, and got better mpgs as the engine got more miles on it. In any event hope you get things sorted. | ||
| Rwcfrank |
How much time does the bike sit idleing? Warming up? Hours run can add up to fuel usage also, especially long warm up periods. | ||
| Electraglider_1997 |
Mke, Here's my take. If your bike is starting and running on both cylinders then you know that your plugs aren't fouled from running too rich. It is colder out and your bike is going to be running on open loop longer which probably means less mpg. Since it is colder out, you probably aren't droning down the highway as much and you are probably spending way more time idling away your fuel at stop signs and stop lights and stop and go traffic. Remember that your transmission and primary chain aren't running in as thin of lube because it takes a very long run time for the Formula + to every get as hot and thin as it gets during the summer. Cold weather works against good mpg any way you look at it. So long as your ULY is running good then just be happy and ride. Quit sweating about dire things that just aren't there anyways. Chill with the weather, dude. One last thing, tape over or stuff some rags into your oil cooler cavity so that it isn't over chilling your oil. I stuffed mine full of clean oil rags and then held them in place by circling the oil cooler assembly with zip lock ties so the rags can't fly out. No reason you need that oil cooler when the temps outside are below 40 or 50 degrees. Make yourself one of my nifty oil temp dipsticks and you'll know for a fact that your oil is not getting any where near as hot as it gets in the summer even with the oil cooler rag free. Here's the archived tutorial on how to make one for your ULY. It'll last as long as your bike. http://www.badweatherbikers.com/buell/messages/142 838/461500.html | ||
| Hughlysses |
I wouldn't worry too much about bad gas mileage on one tank of gas. Maybe you didn't fill it up completely and didn't realize it. Maybe you spent more time idling than you realized this tank. Cold weather definitely affects mileage as EG says above. Now if you're consistently seeing a ~30% decrease in gas mileage tank after tank, that's the time to go digging into things. BTW- I typically go about 150 miles with my 2007 Uly with 2009 engine before the fuel light comes on. Last tank was only ~135 miles (no idea why). With the original 07 engine, I routinely went 170-180 miles before the light came on. | ||
| Etennuly |
I agree with EG and Hugh, but one more thing. Cold starts are hard on spark plugs. If they have been wetted one time they may never come back to "as new". It can run less than great, and still feel acceptable. Cleaning wet plugs has never brought them all of the way back in my experience. So I would say change them to make sure. | ||
| Mke |
Well, I just filled up with 3.5 gallons and last fill up was the same. I'm no longer in the mid-west, so warmup isn't really an issue (temps in the 55-75degrees F range). I usually don't warmup longer than a minute or two. It seems to be running fine other than a bit of a stumbly idle. | ||
| Treefrog |
You didn't say how many tanks you'ved been getting bad mileage. If it was just the one time, it is very possible you got some crappy gas. My 08 XT averages low to mid 40s in commuter mode to work, but not long ago, I had a tank only give me 29 mpg (same commuter route to and from work). Next tank was back into the 40s. Mine also will give better mileage while flogging it, upper 40s-lower 50s. | ||
| Natexlh1000 |
It probably wouldn't be a bad idea to pop off the airbox cover and make sure there aren't mice living in there or something. | ||
| Mke |
Sorry about that.... I've been getting between 100 and 110 miles (according to the trip meter) per 3.5Gal fillup since I purchased it. Note taken on the airbox  ...I'll check that tomorrow. Although, like I said, it seems to be fine on power. Although I'm still baffled on why the check engine light hasn't come on with the O2 sensor disconnected. That's got me worried. | ||
| Natexlh1000 |
The computer is programmed to pay attention to the oxygen sensor at certain specific times so it may be just unaware of it. The type of sensor that these bikes have is the most primitive. They depend upon the exhaust heat to bring them up to the operating temperature. Car sensors have a built-in heater. | ||
| Schwiggy |
This was my experience, I was getting pretty low mileage per tank. When I checked the air filter I found a mouse mansion. I don't really understand how they got in there. But I've been getting better mileage since. 160+ before the light comes on vs the 120-130ish I was getting before on my 06. | ||
| Natexlh1000 |
My "mouse mansion" was in the tail. I cleaned it out twice before laying poison bait on top of my rear tire. Killed 7 of the bastards! I guess once the smell of "Home" is in there, they keep coming. | ||
| Ratbuell |
If you just moved...your EFI needs to re-learn the new environment. Do a TPS reset, and a "learning curve ride", and see if that helps. My bike always gets crappy mileage if I haul it to FL to visit my folks (Maryland mountains to flat-ass sea-level Florida). Runs like poop the whole time I'm there. Get it home...it's fine. If I *ride* it down...it does fine because it learns along the way. |
