'09 XB12scg has trouble idling, CEL codes

[gdisaac07]

Hello everyone

I bought a used 2009 Buell XB12scg about 2 months ago. The bike is fantastic, and only has about 2700 miles on it. However, I have a couple problems with it. The bike has some trouble idling. When it’s cold, it’s mostly not a problem. However, when the bike gets hot (heavy traffic, city riding after pushing it on the highway) or I turn it off and then try to turn it back on again after a couple minutes, the bike fails to idle. It hesitates, pops, backfires (and sometimes misfires), and then dies. Under load, the bike has no problems at all. Above 2500rpm, it will pull and drive happily.

That being said, if I start the bike cold, it will idle forever, with the fan coming on repeatedly to cool the sitting engine down. As of this morning, the bike's CEL light comes on and stays on at bike startup, which is new.

Things I’ve done to diagnose it:

• Changed spark plugs
• Checked to see that the fan is running (runs over 15mph, runs when engine is too hot, runs after bike shut down when engine is hot)
• Used a high-cfm house fan to cool off the left side of the bike after turn-off (bike is able to fire and idle after about 30 minutes of the fan on it, vs 1-2 hours normally)
• Added StarTron to the fuel (Premium 93 octane)
• Reset TPS
• Checked CEL codes (using the ECM jumper method)

The ECM has 4 CEL codes:

• 13 - Oxygen sensor
• 15 - Intake air temperature sensor
• 21 - Interactive muffler control
• 34 - Idle air controller

I don't know if one or more of these CEL issues are causing the rest of the issues. I'm kind of at a loss for where to go from here. Could the IAC failure be causing an O2 sensor failure? Could the IAT sensor be causing the IAC issue? Would the IMC issue be caused by all the spitting and back/misfiring? Am I going to have to replace all of these things?

If you have any other experience with this kind of issue, I’d love some advice. I love the bike but I need it to idle reliably before I get caught in a tunnel at rush hour (again).

Thanks!

 

[gdisaac07]

I spent the day working on diagnosing further.

I disassembled the air box and completely removed everything so I could access the IAC. I cleaned it and the opening it is inserted into with carb cleaner (wasn't that dirty). I also turned a bottle of air in a can upside down and used it to cool the sensor when it was hot and the bike was failing to idle. It improved it temporarily but went back to failing quickly thereafter.

I removed the IATS and hit both the exposed part and body of the part with the compressed air. It made no difference.

The IMC cable slides smoothly. I was able to actuate it by hand but I did not observe it moving when I twisted the throttle in neutral on the stand.

The bike makes this whistling sound when it starts to stumble, like an asthmatic trying to grab for a breath. I took a video of it but won't be able to upload it until later.

 

[AZmidget91]

Intake seals are leaking. What is the AFV?

 

[user_deleted]

hey cole: had something similar last year here. when in open loop like his situation the idle was erratic and a tad to high. ended up being the IAC unit and the base-plate to TB rubber air horn not being properly installed.

The IMC cable slides smoothly. I was able to actuate it by hand but I did not observe it moving when I twisted the throttle in neutral on the stand.

it won't under that circumstance.

 

[TPEHAK]

Perform intake seals leakage test.

 

[Tbone]

Well here is my crazy thought for the day! I do believe, almost positive, this happens. Imagine on a commute in the middle of a very hot day in Texas. Sitting in a traffic jam idling, traffic crawling 20 to 50 ft every 30 seconds then stopping over and over again for an hour. I do believe the throttle body heats up so much that it starts cracking the fuel before it gets burned and changes the idle? In my experience the idle starts jumping up to 1800 or 2000 rpm and back down when it gets hot. It has always done this before and after I have changed the ECM, Intake seals, rocker gaskets, K&N Air Filter, Comfort Kit, breather reroute, etc.... whether I have codes or no codes it is the same behavior. I love commuting on the Buell in the winter because it is a nice heater. In the summer I do not commute on my Buell as much and ride more recreationally away from traffic jams. For the summers i commute more on my 2007 Tiger 1050.

 

[gdisaac07]

@AZmidget91 and @TPEHAK - I also did the intake seal test specified in the manual. I removed the plastic scoop on the left side and the plastic cover on the right and sprayed starter fluid at the intake seals with the bike running and hot. At no point did the revs increase. How do I determine AFV? It is running a bone stock ECM setup with all stock internals, except for a K&N air filter.

@lunaticfringe - I have removed and reinstalled both the IAC and the rubber boot a couple times today. I know it is installed correctly, and was before as well.

@Tbone - This is a problem that is far beyond normal intended operation. The bike will die with the clutch pulled in on decel. It's dangerous this way.

 

[TPEHAK]

Actually RPM should go lower after spraying if there is a leakage. Here is intake seal test



Make sure you spray abundantly all way around.

 

[gdisaac07]

Actually RPM should go lower after spraying if there is a leakage. Here is intake seal test

Using the brake cleaner, like they do in the video, would cause the RPM's to drop. Brake cleaner has Tetrachloroethylene, which is volatile but non-flammable. I used Starter Fluid, which is highly flammable (indeed the manual suggests using propane) and would cause a significant increase in RPM's if it got into the intake system.

I think that both the IAC actuator and O2 sensors are the problem here. Thinking more about it, the problem decreased in severity after cooling the body of the IAC actuator, but quickly came back when the IAC actuator body heated up again. The IAC actuator is essentially just a solenoid, and if it cannot actuate because it is failing with heat, then it would cause a lot of problems.

My next set of questions:

• How can I measure the electrical I/O of the IAC actuator?
• What are the proper electrical I/O values of the IAC actuator?
• How can I measure the electrical output of the IATS?
• What is the proper electrical output of the IATS?
• How can I measure the electrical output of the O2 sensor?
• What is the proper electrical output of the O2 sensor?

I purchased a Buelltooth and Android tablet to check out/reset the CEL codes.

 

[Cooter]

Using the program ECMDroid and the Bluetooth dongle you got from Buelltooth go to "live data" and select those items.

The specific readings can still be found in the free .pdf manual download from Buellmods.com or Buelltooth.com (where you bought the dongle).

I hate throwing money at a guess, especially because you are diagnosing this properly (my kudos to you sir) BUT all three sensors are cheap and easy to replace. The O2 sensors like to get lazy and be a PITA before they fail.

 

[gdisaac07]

Using the program ECMDroid and the Bluetooth dongle you got from Buelltooth go to "live data" and select those items.

The specific readings can still be found in the free .pdf manual download from Buellmods.com or Buelltooth.com (where you bought the dongle).

I spent a lot of time reading up on those specific things tonight. I think I'm going to put some effort into reading outputs of the sensors when I get the BUELLtooth.

I hate throwing money at a guess, especially because you are diagnosing this properly (my kudos to you sir) BUT all three sensors are cheap and easy to replace.

I purchased a few things:



• New Bosch aftermarket oxygen sensor
• New OEM intake air temperature sensor
• New OEM idle air controller actuator

• New BUELLtooth

• New BUELLtooth quick shift assembly (purely for fun, and also because I rode a BMW S1000R and the QS was the absolute best part of that bike)

• Anti-seize lubricant for the O2 sensor

• Amazon Fire Tablet (because it runs Android and ECMDroid is pretty great)

I'm going to replace the sensors and actuator, clear the CEL codes, check the outputs of the sensors, and hopefully it's good to go.

Would an appropriate methodology to test the O2 sensor be to check the AFV output, modify the desired AFV, and then check the new O2 sensor output?

I think I'm also going to re-flash the newest version of the stock '09 tune onto the ECM. Only because I really have no way of knowing what the first owner did to it.

The O2 sensors like to get lazy and be a PITA before they fail.

So I see. Is there a good way to change the O2 sensor that I can do without either rotating the engine or removing the rear shock? I don't have the ability to lift the bike in any other way than spools on the rear axle.

 

[Cooter]

You're on the right track for sure (and x1000% on the S1000R:love_heart testing the O2 is as simple as watching (or datalogging) the output voltage to know if it's giving the ECM the right signal for closed loop operation. ECMDroid is a powerful and easy tool to use for diagnosis.

Your AFV should stay at or near 100. If it's changing drastically, you have a problem. AFV is a global map change, I think it's a rudimentary ham-handed way to do it, but thats that cards were were dealt with both DDFI-2 ('03-'07) and DDFI-3 ('08-'10).

I would shy away from changing any mapping yet. First fix the bike, then modify the bike. You're looking for trouble otherwise. I'm not aware of any "newer, stock tune", but I would recommend the 'race tune' (even the one for a stock muffler). It is a big increase in rideability and power, but resist and only do it after you get your bike sorted.






IMO

 

[Cooter]

Just pull the rear shock. All you need is a bike tie down strap and an A-frame ladder (or rafters in the garage). Hang the bike by the seat rails to let the rear wheel get just off the ground.
Pull the shock, the fan, and use a 7/8" crowsfoot on a 6" wobbly extension. You'll be done before your PBR gets warm.

 

[Tbone]

Removing the rear shock is much easier than rotating the engine. Excellent thread, motivation to get an ecm spy cable or dongle.

 

[gdisaac07]

You're on the right track for sure testing the O2 is as simple as watching (or datalogging) the output voltage to know if it's giving the ECM the right signal for closed loop operation. ECMDroid is a powerful and easy tool to use for diagnosis.

Awesome. Glad my approach has merit!

(and x1000% on the S1000R:love_heart

Honestly, I wasn't a fan of the S1000R as a whole. The I4 just doesn't do it for me. It doesn't have that lovable grunt that the twins have. I also rode a Monster 1200 S (which is kind of a spiritual successor to the XB's IMO) and a 2017 KTM Super Duke R, which I am completely and wholeheartedly in love with the engine of, but don't like how tall it is.

Your AFV should stay at or near 100. If it's changing drastically, you have a problem. AFV is a global map change, I think it's a rudimentary ham-handed way to do it, but thats that cards were were dealt with both DDFI-2 ('03-'07) and DDFI-3 ('08-'10).

I agree. I read a lot on the mapping last night. I think I'm just going to record the initial intended, change it, see the output change, and then change back to the original values.

I would shy away from changing any mapping yet. First fix the bike, then modify the bike. You're looking for trouble otherwise. I'm not aware of any "newer, stock tune", but I would recommend the 'race tune' (even the one for a stock muffler). It is a big increase in rideability and power, but resist and only do it after you get your bike sorted.

I am not sure what stock tunes are out there. The reasons that I was going to reflash the stock tune onto the bike are:

• I don't know if the previous owner modified the tune
• I don't know how the bike's "learn" feature will react to the new sensors

Just pull the rear shock. All you need is a bike tie down strap and an A-frame ladder (or rafters in the garage). Hang the bike by the seat rails to let the rear wheel get just off the ground.
Pull the shock, the fan, and use a 7/8" crowsfoot on a 6" wobbly extension. You'll be done before your PBR gets warm.

I don't have any of those things. I'm doing all this work in the parking lot of my apartment complex. I dropped it off today with a shop in my area with a guy I trust. He used to work on Buells when he was at Harley and now just does custom jobs. He's only replacing the O2 sensor.

Removing the rear shock is much easier than rotating the engine. Excellent thread, motivation to get an ecm spy cable or dongle.

I told him as much and he's going to do it that way. I'm glad this is getting more people on the ECMDroid/BUELLtooth train.

 

[gdisaac07]

Intake seals are leaking. What is the AFV?

I finally got to use my BUELLtooth. I found that my AFV is 143 on the rear cylinder. I set it to 104, just as an experiment, and the bike would fire one cycle and then die. Four revolutions and then it dies. I set it to 143 again and it runs enough for me to ride it. Where do I go with this? Should I just replace the intake seals anyways? Will it change dramatically when I finally have the O2 sensor replaced with a new one?

I took the bike back from the shop because they hadn't started working on it yet and I found a spot I could suspend it. I successfully pulled the shock and was able to pull 3 of the 4 bolts anchoring the fan to the bike. However, the fourth one, found on the bottom, will not move. I stripped the head, then Dremel'd a flathead pattern on it, and I still couldn't remove it with the flathead. I still need to change the O2 sensor, so I'm going to try again tomorrow with a screw tap. I'll have to get a new screw to replace the old one.

Finally, the bike is telling me that my exhaust valve is stuck open. How do I fix that?

 

[Cooter]

Does it have stock exhaust with the valve functional, or something else?

 

[gdisaac07]

Does it have stock exhaust with the valve functional, or something else?

Yes. Completely stock.

 

[TPEHAK]

Adjust exhaust valve according service manual. While adjusting make sure the valve moves when you pull and release the cable.

If you feel you can strip bolt head do not fight it, just spray liquid wrench on it and let it sit for a day , then unscrew it.

Also spray liquid wrench on O2 sensor and let it sit for a day before unscrewing it. Make sure you have O2 sensor wrench adapter to unscrew it. Google how to remove O2 sensor on Buell to be familiar with process and to not brake anything else.

 

[gdisaac07]

Adjust exhaust valve according service manual. While adjusting make sure the valve moves when you pull and release the cable.

I will do this!

Update on the bike:

1. I replaced the IAC actuator and IAT sensor. Neither made any difference.
2. I spent some time replacing the O2 sensor. However, I discovered that the old O2 sensor wasn't bad. The new O2 sensor is providing the same "Always Lean" CEL code that the old one is. Furthermore, even after re-burning a stock BUE2D map onto the bike, the issue persisted. This leads me to fueling.

It is obvious that the bike is getting the right amount of air, but insufficient amounts of fuel. AFV is at 143 or higher. Idle will still not happen. My next course of action is the following:

2. Remove fuel pump assembly and replace fuel pump, fuel pressure regulator, fuel filter, and fuel strainer
3. Replace injectors
4. Replace intake seals
5. Replace ignition coil
6. Replace spark plug wires

The things I've done to test these three issues:

2. For the fuel pump, I used ECMDroid and the BUELLtooth to test the fuel pump. It's giving the typical whine, but it's a cheap part and if I'm going to spend a couple hours disassembling the fuel pump assembly/removing the swingarm, I'm just going to put a new pump in. I'm also going to check grounding of the pump. The bike is 9 years old with only 2,700 miles on it, so I assume the fuel filter is garbage because of old fuel sitting.
3. The injectors click evenly front and back when I test them using ECMDroid and the BUELLtooth. If the new fuel pump/filter/strainer assembly does not work, then this will be my next task to change. I've put StarTron in the fuel to clean the injectors, but it is possible that they are just bad for some reason.
4. The intake seals seem to be a problem, regardless of how many miles are on the bike. When I did the intake seal test, I noticed no problems. But if I'm going to disassemble the top part of the bike to replace the injectors, it's not that much more difficult to replace the intake seals.

Parts that I ordered:

• Fuel Pump and Regulator: https://www.amazon.com/gp/product/B00S25Q82Y/
• Fuel Strainer: https://www.amazon.com/gp/product/B002173E0I/
• Fuel Filter: https://www.amazon.com/gp/product/B000C6MLP4/
• Viton O Rings: https://www.mcmaster.com/#9464K543
• Ignition Coil: https://st-paul-harley-davidson-bue...ell-ignition-coil-all-2003-2010-xb-models-b5y
• Spark Plug Wires: https://st-paul-harley-davidson-bue...-02a8c-buell-oem-spark-plug-wire-set-pair-b1m
• Intake Seals: https://www.denniskirk.com/genuine-...d-seal-blue-26995-97-x.ph26258.prd/H26258.sku

I haven't ordered new injectors.

I guess this is now my winter project. I'm sad that I haven't been able to get this thing working this season. I just want the baby to run!