xb9sx backfiring & running rough

[Lbxb9sx]

Hey everyone! I apologize if this post gets lengthy, but I want to provide anyone that may help diagnose my problem with as much information as possible! My bike is a 2009 xb9sx. It has recently started running rough, especially in the 2200-4000rpm range. The bike has always had a bit of a stutter in this rpm range, but has recently developed a "popping" coming from the airbox, excessive backfiring on both acceleration and deceleration, and even dies on occasion when the throttle is twisted. Both spark plugs are excessively fouled as well.

The bike idles perfectly, and the symptoms really only seem to occur when the bike warms up. The popping and backfiring begin first, followed shortly after by stalling and dying when any throttle at all is given. I have recently replaced the 02 sensor, both plugs, and head temperature sensor. ECMspy recognizes the fault code 'rear cylinder always rich', however no check engine lights have been present.

Additionally, the bike smells as if it is running very rich, bad enough that I usually smell like unburnt fuel after riding the bike, and both spark plugs are always black with carbon. I have sprayed carb cleaner near the intake gaskets on both cylinders, with no increase in rpm.

As far as mods go, the only additions to the bike are a Drummer exhaust and K&N filter. Kevin at Drummer has helped immensely over the phone, so I want to give a HUGE shoutout to him for all the help he has provided! Thank you all in advance for any information you may be able to give.

 

[Nubicon]

I would check the ignition coil.

 

[user_deleted]

As far as mods go, the only additions to the bike are a Drummer exhaust and K&N filter. Kevin at Drummer has helped immensely over the phone, so I want to give a HUGE shoutout to him for all the help he has provided!

can't grasp your basis for these accolades when the obvious appearance is that you joined this board and composed your first post to seek help for unresolved major problems?
having said that you have several potential maladies that all need checked as follows:
1-ANY fuel aromas while either idling/run-mode/shut-off is cause for serious concern. you clearly have excess fuel delivery to the cylinders via the injection system. confirmed by fuel soaked plugs.
2-O2 sensor has no bearing during initial start-up warm-up mode as it comes into play on a warm motor operating in closed-loop mode.
3-"after-firing" out the muffler is from excess fuel during run mode and/or in decel mode.....back-firing up thru the TB intake horn is either an intake valve issue or "leanness" of fuel mapping.
4-DO THIS: since you have EcmSpy check the maps specifically the fuel. have they been altered or mis-matched by some idiot accessing your ecm and playing with the tables? CHECK THEM
NEXT: check the AFV value. climbing way past value of 100? if so needs to be resolved.
lastly and most likely: have you ever reset your tps unit? 2009 done manually without external software, etc. it's simple and it's explained in both your owners and service manual. perform this simple reset.
regardless of accrued mileage which you did not mention....your symptoms classic TPS unit headed to death row.

 

[Lbxb9sx]

My apologies, I was unaware it was wrong to express gratitude for someone who has offered a great deal of support over the phone in trying to fix these issues in my first post. That aside, it is highly possible that the fuel maps are all sorts of off. The previous owner of the bike mentioned that he installed an aftermarket exhaust (he had no idea what brand) but did not like how loud it made the bike, so he reinstalled the stock exhaust. The TPS has been reset both manually, as well as using ECMspy. Mileage is near 3,200. I will check the AFV's shortly.

 

[TyMcFly]

So just to clarify. You have a drummer and a K&N but not the race ECM or stock ECM with race maps flashes onto it? When is the last time you have done a TPS reset? I used to get backfiring through the intake when I had a bad battery connection, but cleaning up the connection fixed most of that issue.

Edit: After seeing your reply it looks like you've answered my questions. Maybe check your ignition wires, plug gaps or like others have mentioned the fuel maps. Personally I would just reflash one on there. These are a lot of data points to look at that could be overlooked. Flashing the correct one on again could eliminate the maps as a possible cause.

 

[Lbxb9sx]

I will look into the fuel maps and grounding points/other connections as well. I have a bad feeling about the TPS though, just as lunaticfringe mentioned. I'll see what I can come up with and check in with any updates!

 

[ocgreenmachine]

The TPS sensor is a relatively inexpensive part from Duralast you can pick up from autozone ($80 ish) and takes very little time to replace, so don't worry too much about it being an enormous or very expensive task if it turns out to be the TPS sensor.

 

[Lbxb9sx]

Just got done logging data with ECMspy. My AFV is at 108% for both front and rear cylinders. TPS is showing .44V/4.2 degrees at idle. The AFV seems high, my next question is what can be done to correct this? Maps? If so, does anyone have any idea where to find either a 2009 XB9 race map? Sorry for my ignorance, Buells are totally new to me :apathy:

 

[user_deleted]

The AFV seems high, my next question is what can be done to correct this? Maps?

i previously mentioned this and you'll be chasing your tail until it's accomplished. since you "data-logged" i would reach out for either readyxb or gunther and have them look at the datalog that demonstrates the changing AFV values and see if there's a problem and if so where does it lie. you also mentioned PO modded the bike and dicked with stuff. you have no idea whether he accessed the ecm and screwed with it. nothing can be resolved till the existing ecm content including maps is sorted thru.
lastly....AFV values change constantly depending on a variety of parameters and conditions including altitude, humidity, temps, riding conditions. your ecm has "mixture" targets and when in open loop over a period of time adjusts the afv accordingly to compensate. i previously mentioned that if the AFV value is climbing "way over" reading of 100 it's pointing to a component/sensor problem. 108 is NOT "way over".

 

[ReadyXB]

Good advice provided above. I'd be happy to take a look at the datalog, if you are willing to work with suggestions. Will likely need the current EEPROM (not just fuel maps) as well for comparison to stock.