| Author | Message | ||
     Pauley2000 |
09 XT stock. Engineer at Erik Buell Racing called re: my returned race ECM. Said it had learned to 83. Dealer here is next to useless too. Is this anything I can fix myself? Also the HD recommendation for my low rpm stumbles, coughing out etc is to check the grounds. So...Anyone here know if the AFV is something I can set? My dealer plays ignorant (or IS ignorant) and claims all he can do is 'plug it in'. -p | ||
| Xbeau12s |
Learn how to use ECM spy and get the cable. Hook laptop up. If you have some mechanical aptitude you should be able to figure it out fairly easily. It has cured many headaches and anger towards mechanics that don't know what there doing. Then I just get to blame myself! | ||
| Pauley2000 |
I believe ECM spy only works on pre '09 models. Is this not the case??? -p | ||
| Froggy |
83 is a bit on the lean side, but normal. Check for air leaks around the air intake and exhaust. These leaks can confuse the sensors and make it run terrible. ECMspy has limited functionality on the 08+ bikes, but the ECMread+Tunerpro combo work fantastic. | ||
| Pauley2000 |
Froggy, I still have a year of warranty. Bike no longer falls asleep after i push the starter, but does hiccough and sputter and (attempt to) cough out while at low rpms while cold first (3-4miles). Grounding seems possble because the spark gets stronger as the revs increase right? But then why does it go away when it's warm. Same question to you Froggy, wouldn't a leaky box stunt at higher rpms too? Would it stop when warmed up? I'm not talking piping hot here, just warm. Any recommended Air leak checking and Ground proving resourses here? I have a service manual but I don't think it covers these instances. Thanks -p | ||
| Froggy |
Depending on the leak, it can make the bike do funky things, specific RPMs, temperatures, etc. It is possible it has a small hole that once everything warms up and expands it goes away. You can use a can of WD40 to check around the throttle body seals for intake leaks. If you spray it and the bike changes sound (usually revs a little), that means the fluid was able to get past the seals and into the motor. This is something your dealer can easily do for diagnostics. | ||
| Pauley2000 |
check. What about exhaust leaks? -p | ||
| Towpro |
I have a feeling we are looking at this wrong. I think an AFV of 83 means it is only injecting 83% of what is listed in the map, so it is injecting LESS fuel then the original map calls for. This is not CAUSED by a LEAN condition. The ECM "thinks" it sees a RICH condition and is leaning out the maps. The result is the ECM is CAUSING a lean condition. Remember this is a closed loop system where the ECM monitors inputs of Temp, Vacuum, Throttle position, cam or crank position and 02 voltage (maybe a couple more?). Also Remember, Garbage in, garbage out. Modern diagnostics as performed in a shop is based on the assumption that the input (sensor) is either dead, or producing the correct measurements! Vacuum leak: This would cause a lean condition and the ECM would need to run AFV number over 100 to compensate for the vacuum leak. Stuck Fuel Injector: This would cause a rich condition, and the ECM would try to lean out the mixture to compensate for the extra fuel. I think this would also have other symptoms like running bad. Bad O2 sensor. 1#(The sensor does not actually measure oxygen concentration, but rather the amount of oxygen needed to completely oxidize any remaining combustibles in the exhaust gas. Rich mixture causes an oxygen demand. This demand causes a voltage to build up, due to transportation of oxygen ions through the sensor layer. Lean mixture causes low voltage, since there is an oxygen excess.) If the O2 sensor was telling the ECM the engine was Rich, the ECM would keep trying to lean it out. I think a rich condition causes a higher voltage on the 02 sensor. So if the ECM is seeing a little bit higher voltage from the O2 sensor it will try to lean out the mixture. From what I am reading, an 02 failure caused by contaminants causes the probe to report a lean condition and the ECM will try to make the mixture richer. If I am wrong about the AFV numbers being smaller means the ECM is leaning out the mixture, please chip in and tell us. 1# (some facts borrowed from Wikipedia) | ||
| Froggy |
Towpro you are correct. I suggested the leak checks as they can still cause the bike to report rich, and it is pretty easy to check. After that, I would of moved onto things like a bad O2 sensor.  | ||
| Pauley2000 |
Lean according to Michael, one of the engineers @ Erik Buell Racing.  -p | ||
| Rwven |
The ECM is learning lean because it "believes" the bike is running too rich.... | ||
| Pauley2000 |
So how do we un-learn it? It has been better as of late. NOT CURED by any means. My dealer service Mgr. told me HD said any FI issues, no light, check the grounds as first step. Will book the appt today. Towpro, thanks. Rwven, still love the peg extenders. BTW in Newfoundland here we have very dense, damp, cool air at sea level. 80f is THE warm day, so don't blink. Most of my riding is done @ 35f-55f. So...my bike theoretically SHOULD be (but isn't) one of the richer fuelled machines in the herd. -p | ||
| Ratbuell |
Go old school. Pull and read your spark plugs, and go from there. Hard data versus software. I'll take hard data anyday (sorry, Froggy...). | ||
| Froggy |
On a FI bike the plugs only show how the bike was doing at the RPM and throttle position when the ignition was cut. | ||
| Ratbuell |
HUH?? Plugs don't change their color/read instantly...granted, EFI will adapt more quickly than carb (which is, basically, static)...but a rich cylinder will still read darker than a lean cylinder. If the AFV has been out of whack long enough to reset to 83...it ain't just a quickie adjustment going on. It's been in-state (whether rich or lean) for a while, and the plug will show it. The plug read isn't a "fix" or "diagnosis"...just a backup against the information given by the computer. |
