High AFV and lean popping on Decel

Bought a 32,000 mile XBX12X and going through a ton of troubleshooting to get it fixed.

2006 XB12X with the Buell Race exhaust, brand new KN filter.

The bike was down on power, popped like crazy on decel, and had AFV in the 114% range.


I reflashed it with a proper race tune.
Also replaced:

Spark plugs
Intake seals
New fuel pump, filter, hoses, pressure regulator
Injectors cleaned

Plugged open nipple on throttle body
Many TPS resets
Checked the throttle plate rod isn't broken

It was running great for a little while after the fuel pump replacement last month, and then the AFV started creeping up again to 115%.

I have not replaced the Oxygen sensor yet because it looks like a massive pain in the ass, but I have one ready to go in.

Is there anything else I can try or test?

Currently the bike won’t even really run if I set the AFV to 100
I should probably get a log recorded as well, but I don't know what to look for.

Quote:

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Originally Posted by tacopwr

Bought a 32,000 mile XBX12X and going through a ton of troubleshooting to get it fixed.

2006 XB12X with the Buell Race exhaust, brand new KN filter.

The bike was down on power, popped like crazy on decel, and had AFV in the 114% range.


I reflashed it with a proper race tune.
Also replaced:

Spark plugs
Intake seals
New fuel pump, filter, hoses, pressure regulator
Injectors cleaned

Plugged open nipple on throttle body
Many TPS resets
Checked the throttle plate rod isn't broken

It was running great for a little while after the fuel pump replacement last month, and then the AFV started creeping up again to 115%.

I have not replaced the Oxygen sensor yet because it looks like a massive pain in the ass, but I have one ready to go in.

Is there anything else I can try or test?

Currently the bike won’t even really run if I set the AFV to 100
I should probably get a log recorded as well, but I don't know what to look for.

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Wait, so you replaced the intake seals and were cool with that, but didnt replace the O2 sensor because it was a massive pain in the ass? The O2 sensor is much simpler to replace than the intake seals. And depending how you did the intake seals, it would have been even easier to replace the O2 sensor. Hell, when you were replacing the fuel pump it would have taken a few more screws removed to get access to the O2 sensor. Something isnt adding up here.

How do you know the "proper race tune" is truly a "proper race tune"? Did you get one from IDS or just download one from someone on the internet who "knows what they are doing"? Did you reflash the ECM with the stock tune? Did you check to make sure the fuel pump was putting out the proper pressure? New fuel pumps can be bad out of the box. Did you verify that one of the new hoses isnt leaking in the tank? Did you verify the intake seals are still sealing? Did you check the TPS to make sure its functioning correctly?

Yeah, pretty much what he ^^^^^^^^^^^^ said.

Tune came from Revision Moto. I dont know what tune was on it previously as I didnt get any info from the previous owner.


I have not checked fuel pressure with a gauge, but I did run the old pump and confirmed it barely flowed anything. The new pump shot fuel out of the hose perfectly. The bike ran perfect after replacing that and resetting AFV to 100.

I guess I can redo the intake seals see if anything has changed there, but I tried the brake cleaner test and no change in idle was noticeable.

TPS has been reset a few times. It ran great after the last one at temperature, but over the past few weeks the bike started running worse and the AFV went back up.

I guess I’ll just go through everything again. Only so many things it could be, right?

Maybe the fuel filter on the fuel pump clogged again due to debris/contaminants in the tank. Maybe the engine temp sensor is malfunctioning? Maybe the IAT is? What is the voltage on the O2 sensor? I'm assuming you checked it and verified it was bad before purchasing a replacement? So many variables.

I'm still baffled why you think its such a pain the ass to replace the O2 sensor, after doing all that work (and being willing to go back through it all again). Its only 9 easy steps documented in the service book.... ohhhh, thats it.

Lol goddamn you guys are hot about the oxygen sensor. I do have the service manual.
I’ll swap that out this weekend after I get the bike hanging from the rafters again.

I’ll double check the engine temps are correct as well. They were reading correctly last month but who knows now.

OK, dont replace the sensor then. Do whatever you want.

PS. Having the service manual and actually reading it are two separate things.

Here is your award. Sorry the problem wasnt easier to solve.

https://pbs.twimg.com/media/Di0o4NIX...jpg&name=small

Dayum dude what is with your tone?

I bought the oxygen sensor after doing hours and hours of other work. Sorry I didn't install it immediately, when it requires that I hang the bike from the rafters to remove that shock. It’s not the most convenient thing in the world, and requires a bunch of time. I was simply asking for any advice for things I might have missed.

PS I did read the manual.

You're absolutely right. Dont do it. Its not worth your time. Or anyones for that matter.

I hope you make it out of your mom’s basement one day. Get a fukking life.

Quote:

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Originally Posted by 34nineteen

OK, dont replace the sensor then. Do whatever you want.

PS. Having the service manual and actually reading it are two separate things.

Here is your award. Sorry the problem wasnt easier to solve.

https://pbs.twimg.com/media/Di0o4NIX...jpg&name=small

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Gonna leave that post as is. I read through the whole thread and found your most likely problem.

Quote:

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Tune came from Revision Moto.

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That right there is 99% of your issue. Want to actually fix it? Get an ecm from IDS (www.idspd.com) that matches the exhaust you have on the bike. IF it actually *is* a Buell factory P&A race exhaust, then this is the part you need to order. https://idspd.com/xcart/buell-xb12-04-07-pa-ecm.html

Install that, do a TPS reset (I highly recommend the CMI-Lite tool, which is also available from IDS) *CORRECTLY* and most likely your problems will be done and over with.
If it still doesn't run correctly after that, then odds are the O2 sensor could be a problem. It does happen on occasion, but not often. As pointed out above, it is NOT a difficult process to replace it.

Quote:

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Originally Posted by tacopwr

I hope you make it out of your mom’s basement one day. Get a fukking life.

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Wow, what is with all the anger?

If you dont want to replace the O2 sensor, dont do it. I dont care. You're the one who came on here asking for advice on how to fix your motorcycle. I gave you advice, you said it was too much of a pain in the ass.

Quote:

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Originally Posted by tacopwr

I hope you make it out of your mom’s basement one day. Get a fukking life.

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And after someone tries to help you, this is the fast way to find a new hobby somewhere else. You won't get much more help if you can't do better than that.

Quote:

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Originally Posted by d_adams

That right there is 99% of your issue. Want to actually fix it? Get an ecm from IDS (www.idspd.com) that matches the exhaust you have on the bike. IF it actually *is* a Buell factory P&A race exhaust, then this is the part you need to order. https://idspd.com/xcart/buell-xb12-04-07-pa-ecm.html

Install that, do a TPS reset (I highly recommend the CMI-Lite tool, which is also available from IDS) *CORRECTLY* and most likely your problems will be done and over with.
If it still doesn't run correctly after that, then odds are the O2 sensor could be a problem. It does happen on occasion, but not often. As pointed out above, it is NOT a difficult process to replace it.

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So it isn't possible to run the stock ECM (and modified tune) with the Buell race exhaust? I’m pretty certain it is the actual Buell part by looking at the tips. Is there another method of identifying? The ECM ID is BUIEB

It *is* a Buell factory race part (P&A stands for Parts and Accessories) and you can run a stock calibration for a very short time, but it will run lean like yours has. It (the ecm) will try adjusting to correct itself, but there is a limit on how much it can do so before finally running like crap.

I am assuming your exhaust looks like this one. https://www.buellxb.com/forum/showth...XHAUST-Muffler

Yes that is the exhaust that is installed.

Revision Moto sent me the tune base on the ECM and that Exhaust info I provided. Are they known to be untrustworthy?

I will gladly run through everything again this weekend, check intake seals, and replace the O2 sensor. No idea why that guy kept repeating that I would refuse to replace it.
I will get a log as well and hopefully that will tell me if anything is still messing up.

I can try the unknown tune that came on the bike since I saved it, but I flashed with the Revision Moto tune with the assumption that was known to be the correct tune for the exhaust. I assumed the previous owner never updated the tune after installing the exhaust.

Shady dave does some questionable ****.

Seriously, if you want it done right, contact Tim at IDS. They are the OEM manufacturer of the ecm, both stock and race units. Physically, they are the same thing but the race unit does not have the EPA restrictions. Get it from a KNOWN and GOOD source. If you can afford the down time by sending in your original ecm, have them do a re-flash on it at IDS.

Quote:

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Originally Posted by d_adams

Shady dave does some questionable ****.

Seriously, if you want it done right, contact Tim at IDS. They are the OEM manufacturer of the ecm, both stock and race units. Physically, they are the same thing but the race unit does not have the EPA restrictions. Get it from a KNOWN and GOOD source. If you can afford the down time by sending in your original ecm, have them do a re-flash on it at IDS.

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Well that is a bummer. I did get the replacement fuel pump and injectors cleaned by RM as well.
I will check out IDS if this doesn't work out. Thank you for the recommendation.

Quote:

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Originally Posted by d_adams

Shady dave does some questionable ****.

Seriously, if you want it done right, contact Tim at IDS. They are the OEM manufacturer of the ecm, both stock and race units. Physically, they are the same thing but the race unit does not have the EPA restrictions. Get it from a KNOWN and GOOD source. If you can afford the down time by sending in your original ecm, have them do a re-flash on it at IDS.

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Hey Dean, just out of curiosity, what do you believe is the matter with rev-mo tunes? They claim to be the factory tunes for each specific pipe, but I of course have no way to verify that. I bought my dongle through him, and used his Jardine tune which seemed to run better, but I'm in no way an expert.

Quote:

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Originally Posted by tacopwr

I hope you make it out of your mom’s basement one day. Get a fukking life.

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TeaBag? Can it be?

Sir: You have a few things going on there and a few suggestions/things to check as follows:
1-A "backfire" on decel thru the muffler is a fuel or air leak related After-Fire, caused by unspent fuel accumulating down-stream of the exhaust port and igniting inside the exhaust system if a few parameters are reached.
2-Most stock XB9's do NOT pop on decel....Most stock XB12's do NOT pop on decel until the IEV is either over-ridden OR wired-open OR removed.
3-Your ECM is trying to enrichen/add fuel by changing both the injector timing as well as opening duration. Something askew.
4-There have been 3 posts on here in the past 6 weeks of XB owners with satisfactorily running models, who then added a Revision-Moto generic or "recommended tune" who subsequently had both throttle response and overall performance issues with same.
5-Highly unlikely that your O2 sensor is at fault. If you've received either historical fault codes 13 thru 15...it typically is not the related sensor...it is a failing ground. Check all of yours INCLUDING ECM grounds.
6-Carefully check every clamp...connection...mounting point....hanger...flange...for your ENTIRE exhaust system. A crack or leak anywhere on same will result in significant "decel after-firing".
7-If you'd like, I have several ECMSPY CD's and diagnostics cable that have proven generic race maps installed on same that work quite well. Have installed same on probably 25 assorted XB's and gives a nice improvement over stock mapping. I can lend you everything if you'd like and perhaps this generic map would solve your problem?
Let me know via PM if that would help.

He a nice man !