2008 Buell XB12Ss -- Die at idle

[cocoabutterlover]

Whats your location... I have spare TPS you can have it.

I'm on Prince Edward Island Canada.

The TPS OHMs will get measured tonight. As well as Idle Air Control getting cleaned out.

Adjusting the AFV values I will do once I get the IAC cleaned out, injectors leak tested, and intake leak test with carb cleaner. If those all check out, I will then adjust AFV and take it for a test ride.

The reason I was posting voltages for the TPS is because it keeps setting off a low voltage fault in my ECU. I did the wiggle test and I couldn't see anything wrong with it.

Unfortunately, I don't think cleaning my IAC will solve my AFV issue. But tonight I will be screwing around with the bike so we will see.

 

[lowkey]

I am convinced the ECM taking 25% of fuel out of the bike for some reason is a big issue and yes, a leaky injector could cause the AFV to drop like yours is.

You are a genius...
My AFV readings was 78.2 so I reset to 100 the Bike ran very well, but after a while the readings went back to 96.1

Does this mean I still have to check for a leakage at the TB??

No, a value below 100 for GEGO or AFV indicates overly rich from 14.7-1 and a correction is being made by the ECM to remove fueling. A value above 100 is correcting for leaner than 14.7-1, a leaking intake manifold gasket would cause a value above 100 as more air than intended is entering the motor.


Only 3 reasons (actually 4) I can see causing an overly rich condition (real or indicated).

1.) Injector not fully closing as cooter states.
2.) Faulty/dying 02 sensor sending an incorrect reading (bike is not actually richer).
3.) Faulty fuel pressure regulator flowing more than factory regulated pressure to the injectors then intended (fuel map now becomes overly rich). and
4.) If someone messed with the fuel tables with software or changed the EEPROM.

EDIT:

5.) AND if it is a DDFI2 bike and the TPS has been reset to the wrong butterfly degree (zero'd wrong) the ECM will go off the fuel table values you wrongly set the TPS at.

 

[Chicknstripn]

Previous owner also did a big bore kit by boring out stock cases; paired with Jardine exhaust and Race ECU with a custom tune. Buelltooth measured AFV rear @ 75-80%. I tried resetting to 87% once to see if it made a difference, but it went back down. but for now, I just want to focus on mechanical parts and connections; not ECU tuning.


Previous owner claims the bike dyno'd at 135hp and 130 torque.

The above two statements would be my biggest concerns. Obviously the ECM has been molested. Go to www.buellmods.com or the buelltooth website and download a known GOOD stock or RACE map. I would start with a stock map just to see what happens.

Do you have any paperwork that helps you identify the actual size of the motor you’re trying to tune? If indeed your engine has had the “cases bored” that would mean you have at least a 1450cc engine. Without knowing what engine you’re trying to tune you’re seriously guessing. If indeed your engine has been bored over that much it would make more sense that with stock injectors and stock fuel pressure regulator you’re not getting enough fuel and you AFV is super high. Not sure why you’re showing lean.

My 2cents, there are entirely too many unknowns regarding the engine.

And if your bike ever was able to run long enough to show those numbers on a dyno, you have the most powerful naturally aspirated xb12ss I’ve ever heard of!

Give us some more info on the engine, and the “custom” tune if you can.

 

[cocoabutterlover]

When I heard his claim my suspicion went up don't worry. I may run it at the Harley dump in town just to see the numbers they get.

How do I post pictures? Do I need a host site separate to buell xb?

 

[lowkey]

How do I post pictures? Do I need a host site separate to buell xb?

In quick reply at bottom of thread it would be the picture icon 3 in from the right in the options bar across the text box, you can load from a website other than buellxb.com or load off your computer/phone local hard drive, sizing requirements can be a PITA though you can also make an album on this site and host them that way then link them into a thread.

 

[Cooter]

though you can also make an album on this site and host them that way then link them into a thread.

Did not know that trick. Thanks lowkey!:eagerness:

 

[cocoabutterlover]

So heres my OHM readings.

R/W to GRD : 4.24K
Throttle Closed: 6.55K
Throttle Open: 1.85K

I also noticed my fuse & relay box behind battery was quite hot after my short (30 minute) test ride. Is this normal?

 

[user_deleted]

I also noticed my fuse & relay box behind battery was quite hot after my short (30 minute) test ride. Is this normal?

NO. classic case of corrosion that needs addressed immediately.

 

[cocoabutterlover]

Grounds? I haven't touched my grounds under the seat yet.

Do you guys just clean the contact with a wire brush or is there some sort of lubricant/solvent that you recommend using?

I was just going to go the wire brush route.

I did notice that there was dirt and crud by some grounds. Is there a ground on top of the spark coil pack? I noticed one of the bolts, the most rearward was not looking great.

Thanks again for taking the time to help me out.:up:

Something like this applied after cleaning grounds up?

 

[njloco]

Checking your grounds is one of the first things you should have done. Wire brush is fine, I use roller chain spray after I'm done, it has an anti-corrossive in it. The other thing you should have done is check your battery under load, I also put the roller chain spray on the battery terminals and leads.

 

[cocoabutterlover]

Checking your grounds is one of the first things you should have done. Wire brush is fine, I use roller chain spray after I'm done, it has an anti-corrossive in it. The other thing you should have done is check your battery under load, I also put the roller chain spray on the battery terminals and leads.

Battery checks out. Just had the stator and regulator replaced. The stator was in pieces. Dealer tested the battery.

I will update once I get the grounds cleaned properly. It was first on my list 'til the bike died on me the first time since the stator wasn't giving me juice. Won't be able to clean them tonight since I'm helping a friend move.

 

[samuelseggs]

No, a value below 100 for GEGO or AFV indicates overly rich from 14.7-1 and a correction is being made by the ECM to remove fueling. A value above 100 is correcting for leaner than 14.7-1, a leaking intake manifold gasket would cause a value above 100 as more air than intended is entering the motor.


Only 3 reasons (actually 4) I can see causing an overly rich condition (real or indicated).

1.) Injector not fully closing as cooter states.
2.) Faulty/dying 02 sensor sending an incorrect reading (bike is not actually richer).
3.) Faulty fuel pressure regulator flowing more than factory regulated pressure to the injectors then intended (fuel map now becomes overly rich). and
4.) If someone messed with the fuel tables with software or changed the EEPROM.

EDIT:

5.) AND if it is a DDFI2 bike and the TPS has been reset to the wrong butterfly degree (zero'd wrong) the ECM will go off the fuel table values you wrongly set the TPS at.

Thank you,

Okay, I have a spare 02 sensor I'll fix and test again, is there a way I can test for injector not fully closing or faulty pressure regulator. My bike is a 2009 xb9sx DDFI3 BUEZD firmware.

Any idea where i can get fuel map for my firmware?

 

[lowkey]

Thank you,

Okay, I have a spare 02 sensor I'll fix and test again, is there a way I can test for injector not fully closing or faulty pressure regulator. My bike is a 2009 xb9sx DDFI3 BUEZD firmware.

Any idea where i can get fuel map for my firmware?

Yes on testing the injectors if you have software (ECMSpy/ECMDroid/TunerProRT), pull injectors from the fuel rail and with their harness clips still plugged in place each injector in an empty clear water bottle. Use one of the mentioned software features to "test front or rear injector". Watch visually the spray pattern and for drip as it cycles about 6 times. If you are still unsure or want an expert analysis send them to someone like injector dynamics.

As for pump/regulator testing you will need to buy/rent a pressure tester. The issue is getting it to work with the stock fuel line as the pump end is a brass block I've seen only on the Buell, the other end you are dealing with fuel rail end and the tight 90* end of the line to which I've found no "kit" to work with. My solution was to buy a new Buell fuel line and cut my old one up to get the brass block and replacement 90* from the parts store along with regular rubber fuel line. I rent a test kit when needed and just put the buell ends on it for testing. I may consider lending the ends out but do not want the parts to not make their way back to me.

 

[lowkey]

Here is another way to get a rough estimate on pump/regulator flow that I did while waiting for the new line to show up and know for sure.

No software required to do this test.

1.) Disconnect the fuel line from the fuel rail and place 90* end into a measuring cup (I used a 2cycle mixing container as it has a tight measuring scale printed on it).

2.) With stopwatch or smartphone cycle the red toggle button on right hand grip control which will cycle the pump to prime. (IIRC I did this 2 cycle times to get 5 seconds of fuel flow and got 2.4oz of fuel).

3.) Next we do some math to figure out the flow for 1hr as this is what the manufacturer posts for fuel flow of the pump.

2.4 oz @ 5 seconds

28.8 oz @ 60 seconds

1728 oz @ 1 hr = 13.5 gallons per hour

Above is for my pump and is very close to the rated flow in GPH from the MFG. Keep in mind the GPH rated is just the pump without regulator so results will be less GPH because of the flow restriction.

Above is for the pump/regulator used in a 2007 XB12STT so you will need to do the legwork on the pump and regulator used on an 2009 XB9.

 

[cocoabutterlover]

Cleaned off grounds. Didn't really make a difference. But it's good for peace of mind. Plus I found two wires that were not crimped at all under the headlight. So I did those up proper.

 

[cocoabutterlover]

So I finally got to spray some carb cleaner into my intake seals. The very first spray the RPM climbed but then no matter how many times and which location I repeated it at. I could not get it replicated. Either way. New seals are on the way.

Hoping this will fix my biggest issue. Also looking at getting a pump rebuild kit from Lunatic; even if I don't need it now. I'll likely need it in the future.

I took some pictures but am currently having difficulty connecting my phone; but if I succeed. I'll let you guys see the questionable state of the bike up close.

 

[cocoabutterlover]

So I finally picked up new intake seals.

Here's what the previous owner had done.

 

[cocoabutterlover]

Part 2


The ratchet with pivoting head in the last photo helped a lot. Eliminated the need for a stubby wrench.

Also, that bolt that attaches to the coil igniter bracket and the throttle body is a bitch. Couldn't get it re-tightened.

 

[cocoabutterlover]

Final pictures of the intake seal job.

I did grease up the new seals when installing.

After the initial test ride I noticed that the bike still didn't run 100%.
Error code came back again for TPS low voltage/short to ground.

I cleared the code and did the wiggle test. No change. I then re-did the resistance readings. Look for next post.

 

[cocoabutterlover]

4.13 Kohm across power to ground
4.65 Kohm across power and return (throttle closed)
1753 ohm across power and return (throttle full open)
4.77Kohm when returned back to closed.

When I took it out for a ride I did noticed that the idle dropped below 1000 rpm briefly, and whenever I cranked the throttle just a little when taking off, the engine did not sound strong, it sounded almost asthmatic a bit.

So my question is... what is my next step? Samuelseggs offered up his TPS. Do I replace the TPS sensor itself?

I also noticed that my resistance readings are opposite of what was posted earlier on in this post. Is that attributed to the leads being hooked up reverse? or is something ****y.

All helps appreciated.