Help on my 08 Uly - long case

[mcaff]

Hello you all.
I have been following this forum for quite a long time, trying to learn everything I could from your experience. However, I haven´t found by now any user that described issues like I have in my bike, so that´s why I´m starting this new thread. I really appreciate any input you may give. Here´s the story:

I purchased my 08 XB12X in august 2014 with around 9,000 miles on the clock. As far as I know, the only two mods it had were: ECU remaped using ECMSpy or TunerPro (or a mix of both) and the exhaust valve disabled due to a broken and not replaced servo/actuator. By the time I bought it, I had to replace its voltage regulator because it was eating headlight bulbs for breakfast.

Since the first ride on the motorcycle I noticed that its behavior in low RPM was not smooth. By the way let me explain what happens: if I try to ride slowly, say 20-30mph in 2nd or 3rd gear, opening the throttle very very little just to maintain the speed, the engine keeps "failing" all the time. But if I give it a very little more acceleration, it jumps like a horse and is very powerful. So summing up, it´s quite impossible to ride it slowly. For the engine to behave accordingly, it must be accelerating, not just maintaining the speed.

First thing I did was to take it back to the mechanic that tuned its ECU (and every other service the bike needed) for him to make a complete check on the bike. But it was unuseful, it kept behaving badly in low RPMs. After that, trying to solve the problem that to me looked like the electronic injection system, I replaced the following parts: engine temp sensor, O2 sensor, TPS and speed sensor. Recently I followed the advice of a friend and had the intake seals changed also. None of them could solve the problem, the engine still behaves the same way as it did since I first rode the bike.

After all that I feel I have exhausted all options I had trying to make it work. Actually I have two more alternatives in my mind but I don´t really think they´ll solve the problem. One of them would be to try a new ECM if I manage to get one for testing and the other would be to upload a new-unchanged-stock EEPROM to my ECU.

Has anyone experienced such a problem?

Please any advice will be very appreciated.

thank you.

Mario

[user_deleted]

mario: an 8 year old ulysses should not have required any of the costly components you threw at it. and if 1 or more of those components had failed it would have resulted in both a CEL(check engine light) activation as well as a stored fault code. you mentioned neither. your details are abundant but i can't discern if you have a low throttle roll-on stumble...complete engine shut-off...or a "miss" at low speeds. a buell motor that just falls flat on its face during throttle roll-on is fuel related....one that "misses" or "stutters" typically ignition/spark related. my suggestion is this: you need a base-line to work from and how you determine your base-line is by asking this mechanic you mentioned 2 simple things: 1-did your ulysses have this problem PRIOR to him "tuning" the ecm......and 2-have him provide you detailed description of the alleged tune. if it ran fine prior to this tuning session you just found the culprit. also it's critical you do the following:
1-ulysses notorious for bottom of seat pan rubbing against both the ecm and the connector sockets. check seat pan and entire top portion of ecm for rub marks. then with bike warm, idling and seat removed simply tap on the ecm and wiggle the connector plugs. any difference in engine note and you found the problem
2-your bike has approx. 6 critical grounds. check them all thoroughly. i have listed all of them on here many times. they are the wire cluster front steering neck area...braided dog-bone main under airbox base plate....cluster where negative battery cable attaches to frame. REMOVE EVERY SINGLE ONE....clean......clean attachment hardware...clean ground point...reattach.

[Outlaw]

Let's not forget the magic of "Sea Foam" . Just kidding. Couldn't resist.

[mcaff]

mario: an 8 year old ulysses should not have required any of the costly components you threw at it. and if 1 or more of those components had failed it would have resulted in both a CEL(check engine light) activation as well as a stored fault code. you mentioned neither. your details are abundant but i can't discern if you have a low throttle roll-on stumble...complete engine shut-off...or a "miss" at low speeds. a buell motor that just falls flat on its face during throttle roll-on is fuel related....one that "misses" or "stutters" typically ignition/spark related. my suggestion is this: you need a base-line to work from and how you determine your base-line is by asking this mechanic you mentioned 2 simple things: 1-did your ulysses have this problem PRIOR to him "tuning" the ecm......and 2-have him provide you detailed description of the alleged tune. if it ran fine prior to this tuning session you just found the culprit. also it's critical you do the following:
1-ulysses notorious for bottom of seat pan rubbing against both the ecm and the connector sockets. check seat pan and entire top portion of ecm for rub marks. then with bike warm, idling and seat removed simply tap on the ecm and wiggle the connector plugs. any difference in engine note and you found the problem
2-your bike has approx. 6 critical grounds. check them all thoroughly. i have listed all of them on here many times. they are the wire cluster front steering neck area...braided dog-bone main under airbox base plate....cluster where negative battery cable attaches to frame. REMOVE EVERY SINGLE ONE....clean......clean attachment hardware...clean ground point...reattach.

Lunatic, I appreaciate your reply.

Let me be clearer. I did not actually change all of those parts. Some of them I took from the mechanic as a tester. I rode it for several miles, after properly reseting the TPS, to check if it was the problem. And them after realizing it didn´t change a thing, I put the old back in place. The parts I have truly changed were the speed sensor because it failed (speedometer stoped working) and the O2 sensor just because I found it to be worth it as it´s a cheap part.

Regarding the behave of the engine is not a complete shut-off. It is just a stumble or a rough running. RPM is not constant, smooth, but instead it varies up and down very suddenly. Hard to explain by words and gets even harder as I´m not english native speaker.

Now going back to the mechanic/tuner which is a big mistery to me. I left the bike with him for a week and all he could tell me is that, in his opinion, the bike is OK! That made me think what kind of motorcycle he is used to running...
For him this behave I related is not an issue, as he said "it´s everything fine in your bike". So I no further counted on him to get this solved.
The tune he made was crap, as I further researched the EEPROM and found some parametres such AFV min and max set to 100. In other words, he locked the AFV to 100. What I did after that was to have another tuner send me an EEPROM without this crap, just a fuel and ignition maps tuning and uploaded it to the ECU. Yes, the bike run a little better after this, but not 100%.

Two things I forgot to mention that are very weird to me:
1 - sometimes when I do a TPS reset the bike runs perfectly for the first couple of miles. When I first saw this happen I rushed to get a new TPS in place, thinking the sensor was faulting. But it wasn´t, with a new TPS in place the bike did well only for the first couple of miles and after was a crap again.
2 - let´s say I stop the motorcycle and turn it off after a long ride. 5-10 minutes later I turn it back on and voilá, it runs smoothly as it should be for a couple of miles.

Regarding the seat making pressure on the ECM, my mechanic developed and installed on it a kind of shield to avoid this from happening. There is a thick steel plate separating the ECM and its cables from the seat bottom.
I will try to find out these grounds you mentioned.
thanks.

[user_deleted]

Let's not forget the magic of "Sea Foam" . Just kidding. Couldn't resist.

nice pick-up on your part outlaw. make that #4 suggestion on my recommended 'to-do" list.

[user_deleted]

2 - let´s say I stop the motorcycle and turn it off after a long ride. 5-10 minutes later I turn it back on and voilá, it runs smoothly as it should be for a couple of miles.

your symptoms might be heat related and clearly there has been alot of hands working under your airbox base-plate. there are some sensitive components under there including the rubber velocity stack that connects your throttle body assembly to the airbox baseplate. it MUST be installed correctly and clamped with the factory spring clamp. you also need to check the condition of your coil for any signs of weepage, arcing or cracking.....the condition of the plug wires....and the spark plugs themselves. recommend NGK DCPR9EIX if replacing.

[mcaff]

2 - let´s say I stop the motorcycle and turn it off after a long ride. 5-10 minutes later I turn it back on and voilá, it runs smoothly as it should be for a couple of miles.

your symptoms might be heat related and clearly there has been alot of hands working under your airbox base-plate. there are some sensitive components under there including the rubber velocity stack that connects your throttle body assembly to the airbox baseplate. it MUST be installed correctly and clamped with the factory spring clamp. you also need to check the condition of your coil for any signs of weepage, arcing or cracking.....the condition of the plug wires....and the spark plugs themselves. recommend NGK DCPR9EIX if replacing.

I am sure the velocity stack is installed correctly and clamped with the factory thing.

How do I check the coil!? Put a new one in place and test?

Plug wires are the ones that came on it, never replaced them. And spark plugs are brand new, just got a pair of Brisk installed 3 days ago.

[mcaff]

Capture.JPG

Warmed engine up about 5 minutes and these are the parameters shown on ECMSpy. Looks everything ok doesnt it?

[LouWambsganss]

It sounds like you could have a cracked ECM connector. Look at both harness connectors where they pot into the ECM case. Look for any cracking or movement when you apply light finger pressure. The movement of the connectors will actually throw off settings within the ECM like throttle position. If you have and ECMSpy or Buelltooth, you can actually watch the TPS angle change as you press on the connectors. The problem may be happening all the time, but low RPM, low load situations are where the engine is most sensetive to tiny changes in air fuel ratio caused by the constantly fluctuating TPS signal.

ECM Cracks.jpg

You can seal over the cracks with RTV to keep the ECM waterproof. However, to prevent vibration from constantly moving the connectors, you need to bridge the gap from the ECM case to the connectors to create a solid connection. I used a carbon fiber plate on each connector. However, you can really use anything rigid like a large washer or piece of sheetmetal or something. Just epoxy it to the ECM case and to the connector body. Let it cure fully before reinstalling the ECM and plugging in the connectors.

ECM splice.jpg

Remember to do a TPS reset after any work.

You can shim your seat up a little, grind away a little material from the seat pan where the ECM rubs, and/or move the ECM down a little to prevent more damage in the future.

[LouWambsganss]

I think the TPS angle is a little high. 3.8-4.2 degrees is correct at idle if I remember right. 85 degrees when fully open. See my post above about possible ECM problem/fix.