Burning too rich at idle
- Thread starter LazySatyr
- Start date
Help Support Buellxb Forum:
DualSportDad
Well-known member
- Joined
- Oct 21, 2013
- Messages
- 422
Here's my experience with a bad o2 sensor. See why I'm trying to start it the o2 stays at .49 volts for a while. After I get it running and warm up the sensor it goes into closed loop and will idle. As soon as I rev it and hold it at steady rpm the o2 doesn't switch back and fourth like it should. That messed by tune and AFV all up.
I put in a new o2, reset the AFV and took her for a quick ride (about 2 miles) and she was good as new.
Xb9sx won't idle when cold: http://youtu.be/WBn0wa9gtp8
I put in a new o2, reset the AFV and took her for a quick ride (about 2 miles) and she was good as new.
Xb9sx won't idle when cold: http://youtu.be/WBn0wa9gtp8
So i'm almost 100% that there's something clogging the fuel line. Going to have a friend/mechanic pull the fuel pump out tomorrow and see what shape it and the line are in.
But bike has been running better since using the seafoam and the afv number seems to be going down slowly, which i think indicates something is being gradually cleaned.
Also the new battery made a huge difference, bike starts way better and seems to be idling higher (not that i understand how a battery could affect idle)
But bike has been running better since using the seafoam and the afv number seems to be going down slowly, which i think indicates something is being gradually cleaned.
Also the new battery made a huge difference, bike starts way better and seems to be idling higher (not that i understand how a battery could affect idle)
Been a while so apologies, the bike was with a local mechanic the last few days.
Good news is the compression is good on both cylinders and the fueling seems good all round, fuel pump line etc all check out.
Bad news, ignition coil connector are coming loose by themselves, and thus fouling the spark plugs. Also the temp sensor that is supposed to be under the airbox is missing.
New plugs is easy, but has anyone dealt with this issue with the coil? To me it just looks like the two cable which run to the spark plugs just slot into the coil itself, which on a bike the rattles as much as a xb seems like a design flaw. Are there any DIY fixes to secure the connection?
How important is the temp sensor (probably a dumb question, probably very) and does anyone know where i can find one, ebay isn't coming up with anything for me
As always thank you very much for your help.
Good news is the compression is good on both cylinders and the fueling seems good all round, fuel pump line etc all check out.
Bad news, ignition coil connector are coming loose by themselves, and thus fouling the spark plugs. Also the temp sensor that is supposed to be under the airbox is missing.
New plugs is easy, but has anyone dealt with this issue with the coil? To me it just looks like the two cable which run to the spark plugs just slot into the coil itself, which on a bike the rattles as much as a xb seems like a design flaw. Are there any DIY fixes to secure the connection?
How important is the temp sensor (probably a dumb question, probably very) and does anyone know where i can find one, ebay isn't coming up with anything for me
As always thank you very much for your help.
Yeah i know it's impressively bad.
Look i picked this bike up for a song and she runs, if poorly, and honestly i've had the best time working on it thus far.
Plus right now the bike idles, starts right up and runs pretty smoothly except for some minor backfiring and the fact that it will idle out occasionally.
Look i picked this bike up for a song and she runs, if poorly, and honestly i've had the best time working on it thus far.
Plus right now the bike idles, starts right up and runs pretty smoothly except for some minor backfiring and the fact that it will idle out occasionally.
It's OK. I'm not REALLY busting on you. But...remember...ALWAYS check the basics FIRST!! (Making sure all componentry is at least intact IS a basic). I see it over and over again. And often times it wasn't a big issue in the end anyways. Live and learn.....we've all been there in one way or another.
Theycallmecrash
Well-known member
- Joined
- Aug 4, 2012
- Messages
- 2,403
Wait... how is it missing if your ecm is giving you readings?! Sure its not just under the base somewhere? Air temp sensor that is.
Ok bike has new spark plugs, the ngk's that everyone recommended on a thread somewhere on this forum. Cleaned the connections to the coil and checked resistance on the coil and connectors, all good. Fuel line is clear pump is running properly. Start up is solid, got bike to idle at around 1100 but had to turn idle screw a little high (see pic).
But AFV is at 140! I don't really get it, bike is running way better, there's some definite popping when decelerating but engine doesn't die off like it used to.
So at this point i'm thinking i had a compound problem and there is probably just one or two causes left but i have no idea what. All i can think of now is that one of my sensor is bad but i know not which. None of them are bad enough to give a code so how do i test them? Could this be a bad injector? Compression was 115 in the front and 106 in the rear.
here's a ecmspy screen from after a short ride
But AFV is at 140! I don't really get it, bike is running way better, there's some definite popping when decelerating but engine doesn't die off like it used to.
So at this point i'm thinking i had a compound problem and there is probably just one or two causes left but i have no idea what. All i can think of now is that one of my sensor is bad but i know not which. None of them are bad enough to give a code so how do i test them? Could this be a bad injector? Compression was 115 in the front and 106 in the rear.
here's a ecmspy screen from after a short ride
Theycallmecrash
Well-known member
- Joined
- Aug 4, 2012
- Messages
- 2,403
Compression test seems to be a bit weak, mine tested out at 155 each on the dot.
90 is all you really need to run, but yours seems on the low side. Im currently trying to chase a current issue similar but exact opposite problem a 60 AFV with now signs as to why
Did you ever get a fuel pressure reading?
90 is all you really need to run, but yours seems on the low side. Im currently trying to chase a current issue similar but exact opposite problem a 60 AFV with now signs as to why
Did you ever get a fuel pressure reading?
Not trying to be a smart-ass here, but there's LOTS of variable between yours and his. While I agree, it would be nice to see at least 125 cranking compression, battery voltage, starter, temperature of engine, amount of cylinder wash from fuel, and a range of other factors could make the diff here. Once he gets it right and services it with some fresh oil, it just may come back around.
fuel delivery problem
theres no way its needing 40-50% more fuel than the map calls for. that would be values above the max pulsewidth of the injectors at higher rpm. then add the default correction at WOT and youre even higher.
can you datalog and email me the file. i will go over it and see if anything jumps out.
put the laptop in a backpack and ride around for 20-30mins. the file will be less than 2MB.
the only other thing would be some sort of extra air getting in there.
all of this is assuming the sensors are working properly.
i cant express the value of a wideband o2 sensor and a gauge as a diagnostic tool on these things. a worthwhile investment.
theres no way its needing 40-50% more fuel than the map calls for. that would be values above the max pulsewidth of the injectors at higher rpm. then add the default correction at WOT and youre even higher.
can you datalog and email me the file. i will go over it and see if anything jumps out.
put the laptop in a backpack and ride around for 20-30mins. the file will be less than 2MB.
the only other thing would be some sort of extra air getting in there.
all of this is assuming the sensors are working properly.
i cant express the value of a wideband o2 sensor and a gauge as a diagnostic tool on these things. a worthwhile investment.
buellxb9rs
Well-known member
- Joined
- Jun 11, 2012
- Messages
- 1,334
Make sure the min and max afv is set correctly and go from there. It could be 02 sensor, fuel pump, etc
Ok so i go to start up the bike this morning and it struggles and no longer wants to idle. I plug in ecmspy and lo the ECM has set its AFV to 110%, got it running at this setting but so much backfiring and throttle lag etc.
Reset the AFV to 140 where it had been yesterday and everything got better. Haven't gone for a ride but did log some revving and idling. I'll post that and a ride log soon
Reset the AFV to 140 where it had been yesterday and everything got better. Haven't gone for a ride but did log some revving and idling. I'll post that and a ride log soon
also i clogged the air intake scoop with a towel to see how it would effect the idle and nothing changed, not even a little, would this suggest it's getting air elsewhere? Especially being at altitude this seems super strange and i gotta think either the o2 sensor is bad or there is a leak somewhere in the throttle body i didn't find.
gonna swing down to autozone and pick up the bosch 12014 see if it makes a difference.
gonna swing down to autozone and pick up the bosch 12014 see if it makes a difference.
Similar threads
Latest posts
-
-
-
-
-
-
Buell XB Parts Catalogs that are available online at HD.
- Latest: Mike Workman