| Author | Message | ||
     Etennuly |
New Theory #752. I may have found something today(like I haven't said that before). 85F degrees today, 65 mph light came on, I turned it up to 70 and run skip was back. I got to my destination 33 miles out, and was thinking about why the only code any of us have seen has been the one for the o2 sensor. The bike runs great, the fuel mileage is off by the same 2 - 3 mpg that it has been for sometime. It struck me that the heat is the issue from the exhaust ports out. I was feeling a lot of heat at the pegs. I'm thinking potato in the tail pipe. I was then thinking what if the exhaust actuator valve is closed at 3500 RPM while cruising at 70 down the Interstate. Back when I ran through the FL/RS, when I hit 90 it smoothed out and the light went off. The valve was open above 4000 or so. So I wired open the exhaust valve(it works fine otherwise) to see if it would let more exhaust heat out on my return trip. It changed it for sure. I ran steady throttle at 75 mph for fifteen miles, I cranked it to 80 for a bit and the light came on and run/skip hit for just long enough to close the throttle, then it went off. I am thinking that since the problem started at about 10,000 miles, and gradually got worse(now at 47650) the muffler could be plugging up with carbon. With the valve open it may be relieving some of the heat from a restriction. It made a difference, and made it react differently, and better to throttle closing. I am going to open up the can sometime in the next few weeks to have a look. It really needs painted anyway. I will have to be gentle as to not knock any carbon loose, so I will cut it open with the plasma cutter. What is a little welding before painting anyway?  Ever heard of anyone having the problem with a non stock exhaust can? | ||
| Natexlh1000 |
What if you go the other route and leave the cable unplugged and allow the valve to close all the time? If your theory is correct, the additional backpressure of the exhaust going through all three chambers would make the problem worse. If you can make your problem WORSE, you have found the problem! | ||
| Sekalilgai |
...I think what you said earlier bears merit...the engine is tuned....pretty tight already and it may not take all that much to get her 'too hot'. Had o2 code on mine too. With 02 replaced, mileage is back. FWIW, I just went to the race can...we might find out if the poor motor overheats still.... | ||
| Florida_lime |
When I first had the problem, I wired my exhaust valve open -- it didn't make ANY difference with my Uly's problems. | ||
| Ksc12c |
Mine has the same problem. It only appears when I'm doing a road trip of 300 miles or more or when riding two up. I suspect it might be over heating or thinks its overheating? I first suspected loose shorted wires under the seat or the ecm connectors. Last time it happened I looked at the trouble codes and it called out the o2 sensor. Anybody have any luck replacing the o2 sensor to correct the fix? | ||
| Etennuly |
Sekalilgai, changed his o2 sensor with no difference. I fixed wire problems all over, and many other things with no change. This exhaust thing is the second thing that has given me at least something different. The first was the comfort kit RSS. I have a new o2 sensor in my office waiting for me to get to it. I may do that while I'm surgically hacking at the muffler. | ||
| Buellerxt |
Is this only a pre-2008 Uly thing? If not, what is the issue? Gas mileage falls and the bike starts 'skipping' at some point? Thanks. | ||
| Ksc12c |
For me, It's more annoying then anything. The first couple of times it happened I was worried about being stranded in the middle of nowhere. That hasn't happened yet. I've learned to basically ignore but, when it happens passing a 18 wheeler it's not a confidence building experience. | ||
| Sekalilgai |
Actually I did a bad...changed both o2 sensor and re-adjusted cam-timing at the same time. Broke my change-one-thing-at-a-time rule. But I got limited testing after that and could not get run-skip to kick off. But at the time the temps were only in the high 70s. AFV 100, noted that mileage on the next tank was back to 'normal', or about 44. After a tank of that, I did the race-can and did about 460 miles to include ideal run-skip conditions and could not get it to fail. AFV 99.5, mileage down to 41. Here's another red herring. When I first got the bike, AFV was always pretty steady 97-102 and never wandered very far. When I started seeing o2 codes being set, my AFV had crept up to 115-118. Now after the new o2 (and cam and exhaust), the AFV is steady at 99.5. Sorry for the non-definitive 'answer'. I read someplace that the typical unheated o2 sensor is only good for 30-50k as the soot buildup will interfere with its operation. It is not a particularly tough install, esp for those of us who have had the joy of pulling the fan. It already comes with the anti-sieze on the threads so save yourself the trip to the autostore.... (not like me who didn't check). Ken | ||
| Etennuly |
So do you think the race can made a difference? | ||
| Wolfridgerider |
I have had a modified exhaust on the Uly, TT & Firebolt almost from the time I brought them home. I have never had a run-skip happen. For what that is worth.... | ||
| Sekalilgai |
I'm guessing the race-can didn't make a difference. I'm thinking it was somewhere between the ignition advance and the o2 sensor. When I adjusted the cam sensor, it took like 1/2 of one of the big tick marks of additional advance to 'correct' it ...guessing that was about 4degrees. AFV stabilized, no run-skip and mileage was back. This was before I added the race can. With the race can, there are two variables there, the can and a new map (with even more ignition advance). If I didn't enjoy removing the muffler so much, I'd reverse it to test.....but I hate that job. Ken (Message edited by sekalilgai on May 10, 2010) | ||
| Etennuly |
So Mr. Ken.....Question number 1. Are you saying the barricade orange '06 Ulysses that you so much like to work on, is no longer having the run skip issue as far as you can tell? A simple 'yes that is correct' will suffice. Question number 2. If that answer is indeed yes, am I correct in assuming that you may possibly have corrected the problem by; changing the o2 sensor, changing the timing + about 4 degrees, resetting the fuel maps to @100, and changing to the race muffler? Again a simple yes will do. Question number 3. If that is a correct assumption, then the problem that you feel is bothering you, is that you did not make these changes exactly one at a time, therefore you cannot pin point the exact cure, if indeed it is cured? Again a simple yes will suffice. Personally I do not care, if these four changes fixes it, I will replicate your repair procedures one step at a time to find if I get a good result. These things are peanuts to what other things I have done to find the cure for flashy light run/skip at touring speeds in warm to hot weather. Thanks for posting your tests Ken.  | ||
| Florida_lime |
For me, It's more annoying then anything. The first couple of times it happened I was worried about being stranded in the middle of nowhere. That hasn't happened yet. That's what I thought, since I made it through 550 miles of skip spark on one trip last year. It was doing it again going through Georgia on this past Easter weekend, and died completely. $350 rental car...... Saturday afternoon I was running late into work. 90 degrees, heavy throttle -- I had all 3 issues. Running miss or stumble, the O2 sensor - Check engine light, and the the Skip Spark BS.  Keep us posted ! | ||
| Buellerxt |
Does this happen on 2008's and later? What is it, engine missing, at higher speeds, in hot weather? I had a 'miss' the other day at about 70 mph and though it surprised and concerned me I talked myself into thinking that maybe I moved my throttle hand a bit, and it is sensitive, since it didn't happen again. It wasn't a good feeling. Ths. | ||
| Florida_lime |
Does this happen on 2008's and later ? Mine is an '07, Etennuly has an '06, Sekalilgai's profile says '06, Ksc12c's profile says '06..... | ||
| Sekalilgai |
Yes, Yes, YES! (feel like an insurance commercial) Too many changes all without sufficient hot weather in-between. For now, it appears to have 'gone'. We can swap bikes here at the Res ride and do our best to kick off the run-skip if you'd like. Ken | ||
| Slowride |
Here is an semi educated guess.... What octane rating is the gas you are running? The lower the octane the lower the (think oxygen) burn = less heat The higher the octane the higher the (think Oxygen)burn = more heat | ||
| Etennuly |
Well I am going to get into doing all four things asap. If time and temperatures allow I will try one at a time for testing purposes. I really want to have it cured before the Res Ride at the end of the month.  I better hurry up! | ||
| Natexlh1000 |
The octane rating refers to a gasoline's resistance to pre-ignite due to compression. Nothing to do with Oxygen content or energy content. Site: http://en.wikipedia.org/wiki/Octane_rating | ||
| Slowride |
Thanks Nate, I am full of useless semi educated guess type references. Doesn't change the fact that the "CHEAPER" gas 87 octane that we're not supposed to run keeps the bike running cooler with no perceived ill effects. | ||
| Yamafreak |
I do ping more with 87 octane  | ||
| Nobuell |
My bike never pings when using the correct octane rating. I almost immediately do notice pinging and poor operation when filling with the lower octane ratings. | ||
| Etennuly |
Actually higher octane burns longer, further down the power stroke, making more efficient power each time it fires, that in turn lets it run cooler because it does not have to run as hard to make the same amount of power. The lower octane causes more of a quick burn at the top of the power stroke not pushing the piston all of the way down the cylinder, and causes pinging because it will flash burn prior to the spark plug firing due to hi compression and or ignition timing being off. The higher octane fuel will make it run cooler and produce more usable power. Let's not make this into an octane comparison thread, please?!  Several of us are working through a problem that that won't help. But thanks for your input. I am not opposed to thread hi-jacking, I have been known to be part of making that happen now and again.  It is just that we are so close to a fix after three years of probing, fixing, dealer attempts, testing-retesting, and stressing, now it is possible that we are looking at a repair that may actually work.  Summer riding season is here and I don't want a repeat of last year's failed long trip from this issue again. I have four long summer trips planned. It is a non issue on back road riding and ripping around, but the bike is just un-usable for high speed cruising above 65F degrees. Next question, if the exhaust valve is wired open, will that cause a red light to come on. I don't think it would because it is still plugged in and I didn't tell it that the cable was unhooked. Oh and it runs like shit until it is completely warmed up now. If that is so, then my bike ran into the red light from heat and not into the run/skip today. 72F on the slab at 70 mph, up to 80 for a bit on a 30 mile ride. Those conditions would have made run/skip every time before blocking the valve open. I did not have time to check for codes yet. | ||
| Mnrider |
I wish I could help. I feel so helpless The timing thing does make sense though. (Message edited by mnrider on May 11, 2010) | ||
| Sekalilgai |
it was bloody cold when we left Pittsburgh this morning...here in Tampa it feels like a furnace....too bad I don't have the Uly Vern...I'd do some testing for you... | ||
| Florida_lime |
Head east and south from Tampa, and you can "test" mine all you want.  | ||
| Sekalilgai |
Florida_lime I went back and re-read some of your troubleshooting so far. Has O2 been changed? Re: fuel pressure, I had to pull my pump last year due to chaffing and replaced the filter (while I was at it) and it didn't make a difference to run-skip. Last time (run-skip pt99) sounded like your dealer had replicated the problem, did they come to a diagnosis? I'm locked up at a job tomorrow (and home Thurs), else I'd head your way! | ||
| Sekalilgai |
BTW Vern I don't think leaving the AMC servo connected but nothing attached to the cable will throw any codes. At the very worst, we could disable it in EPROM if needed. | ||
| Florida_lime |
O2 sensor has been changed at least once, but I don't think it has been changed since the problems started last year. The dealer in Macon (over 500 miles away from me) was able to duplicate the problem, but they didn't want to spend any more time and $ to work on it, even when I asked them to ! They felt fuel pressure was a possible issue - fuel pump or injectors. I may try replacing the cam position sensor before I try anything else. |
