Idle problem

[Honda_Sol]

Hey guys I have a 2005 Buell lightning xb12s. Race ECM, k&n, breather mod, and Altus exhaust. Ran perfect until the other day. Went to start it up and it ran fine for a second and then surged and died. It will stay running if I give it a little gas. When's its cold it will pop through the intake when trying to take off from a stop Once it warms up it's better. Still hesitates for a second once I come to a stop. Then it catches itself and is good. Also if I shut it down and start it up when it's warm it kinda bogs down some for a few mins. I have changed plugs, inspected wires, and tps reset. Nothing's really helped. Plugs are the Ngk 9's. 2316. Always used them. I haven't changed anything from the previous set up it just started happening. Thanks

 

[go cytocis]

Dumb simple things first. Did you pick up a tank of shitty gas? Battery's good with tight connections? Dirty injectors? Intake vacuum leak anywhere? Pinched vent tubes or plugged valve?

If none of these bring a solution, and you've already done plugs, wires, & TPS, you may be looking further upstream at the coils & ignition module. Also the O2, IAT, ET, & CP sensors are possibilities.

Good luck!

 

[Honda_Sol]

The gas is good unless I got shitty has twice. Should I try some seafoam in the gas tank? I'll double check the battery but it fires up no problem. How do I check for vaccine leak? I don't hear one at all. Wouldn't the sensors throw off a check engine light?

 

[go cytocis]

Should I try some seafoam in the gas tank?

I have no experience with seafoam, but I suppose it can't hurt(?). Perhaps also a bottle of injector cleaner is worth a try.

How do I check for vaccine leak?

A visual inspection of rubber boots first, then you can try spraying starter fluid around the intake tract while the bike's idling to check if the revs rise. A stethoscope may also help you locate a leak.

Wouldn't the sensors throw off a check engine light?

Not necessarily, in my experience, but I'm sure no authority here either.

 

[Honda_Sol]

Okay I'll try the injector cleaner and look for vacuum leaks. I'll check the battery and go from there. Thanks for the help! Anyone else have ideas?

 

[Honda_Sol]

I tried the starter fluid. Couldn't find any vacuum leaks. I cleaned the throttle body while I was in there. It was pretty dirty. Battery checked good. 12.3 volts before starting. 14.3 while revving. I'll still try fuel injector cleaner tomorrow hopefully. Here are some pictures of it all. Everything looks good except a little oil to the left side in the picture near the breather? Any ideas?

Also how do you post videos. I have a video of it acting up on my iphone and wanted to post it. The pictures where better quality but it would let me upload them with petter quality due to file size.

 

[BuellRonin]

2005 XB12Scg

I had somewhat similar issues, but not 100% the same. Started surging out of the blue and got worse from there. It would be ok when warm, then act like poop on stop and go breaks. It would stall as I rolled to a stop as well. I thought I had bad gas as well. Went through normal "good" advice given on here, but still couldn't peg it. No CEL or codes.

I finally got a code and figured out what was happening after I tried replace parts (plug wires, ignition coil (which is really rock solid, has to be a serious crack in it, as its a passive device. Per HD techs), TPS (warranty Autozone), IAT (not the issue), Head temp (just replaced as wires were exposed, not the main problem).

It was my 02 sensor, but it didn't throw a code for about a month or so. I had over filled my oil (stupid) and shit boxed the 02 sensor. Once I replaced it, boom. Magic.

Here are some cross reference part numbers:
I used the Bosch.

O2 SENSORS: GM OEM = 25162693
NTK = 21002
Airtex = 553071
Bosch = 12014
Denso = 234-1001
Walker = 250-21001
SNG = SN1-15

 

[Honda_Sol]

Where is the o2 sensor located on these things? Have a part number? Or a way to test it? I see you edited it lol thanks.

 

[BuellRonin]

O2 Sensor is behind the fan on rear head on the brake side of bike (apologize if terminology is incorrect)...and hard to get to. There is no "cheat" that I found to get to it. You have to remove the shock and fan to get it out properly. It wasn't hard, but make sure you take your time.

I am sure there is a test procedure for it, but since I got the code I replaced it.

 

[Honda_Sol]

Gotcha, haven't found the test procedure yet. Been googling it. Can I turn off the o2 with ecm spy, reset afv and then see what it does?

 

[BuellRonin]

Um, not sure. I'm not a super Guru like most on this forum. Good with a wrench, a mechanic I am not.

There are some manuals you can download at the top and look at the test procedures there.

From your first photo just past the braided wire, look just behind that. There is a gap you can look in the gap between the frame and the header...its sitting right there. Seat needs to be off.

Cheers!

 

[adjwoolley]

It was my 02 sensor, but it didn't throw a code for about a month or so. I had over filled my oil (stupid) and shit boxed the 02 sensor. Once I replaced it, boom. Magic.

over filling oil will ruin the sensor? mine was running weird before i tore the motor down and it had 3 quarts of oil in it.

 

[BuellRonin]

Yea, I overfilled it way past the fill line. Just was in a hurry and shoved some oil in to get to a ride.

Overfilling can do funny things with the pressure in the various lines and jets throughout the engine, but generally a small overfill will do no damage. It causes the ECM to compensate incorrectly. I found a better explanation a while back, but can't find it now.

But drained the oil, and properly filled her to 2.5 quarts. New 02 sensor was needed because ECM was trying to fix the irregularity and made the back run lean when it didn't need to, basically trashing my O2 sensor in the process. Again, there is a better/proper explanation, I'm just paraphrasing.

Cheers!

 

[WIGGLE2]

^^ The only way I can see this as plausible, is if it would push oil out the breather tube and the the engine ingests it through the intake. Even then, it would have to be over an extended period of time. No doubting you may have had a bad O2 sensor, but it was more than likely not caused from too high of an oil level. Too much oil in the swingarm WILL at most make a serious mess, but won't hurt much.

 

[Cody04xb12s]

My bike is doing the exact same thing...only when cold and every once in a while.

 

[Honda_Sol]

Intake seals is probable cause pretty sure. Got a lot of help from the buellxb Facebook club