| Author | Message | ||
     Dcapito |
For an '01 X1 with race ECM: Does anyone know how to turn off the O2 sensor in order to eliminate closed loop operation? Regards, Derek | ||
| Buellisticx1 |
Yes, I also have the O2 turned off and increased all the values by 4 in all cells in closed loop area for get a AFR of 14:1 and not 14.7:1. the bike runs more richer and smoother and it now it runs a better then before. The tuner told me that most air-cooled V twins like to run at 14.0/13.5:1 AFR in the closed loop area so you can run the engine a little richer so that was my target. It was increased all the values in closed loop area of the fuel map to get a AFR of 14:1, so now the engine runs smoother and better. So the O2 was turned off Now with my setup/mods and the O2 off my bike runs much and much better then before in midrange. You get a solid increase in horsepower and torque in midrange. Open ECMSPY diagnostic tab and just click on that box (O2 sensor off) and burn and it toggles.  Hope helps. Regards. (Message edited by buellisticx1 on October 31, 2009) | ||
| Dcapito |
Cool. Thanks! I saw that check box, but was wondering about this: The creator of the TuneEdit software (see http://www.tuneboy.com.au/BuyNow/BuyNow.html), which presumably does most of the same things as ECMSpy, said that it's a bad idea to disable the O2 sensor, as the ECM uses this to correct for ambient conditions. That no corrections for ambient conditions would happen without it makes no sense to me. Doesn't the ECM monitor temperature and pressure sensors for this purpose? Also it seems that the AFV values should be set to 100 when running in open loop. Is this correct? What about the default open loop correction? I'll assume 100%? But what does "open loop enrich delay" do? Is this the time between when the ECM goes into open loop, and when it applies the open loop correction? I suppose if the correction is 100%, then the delay does not matter, but probably should be set at zero? Regards, Derek | ||
| Buellisticx1 |
I will try to be as detailed as I can. Have you checked your AFV?.... What altitude are you at?..... You should know: The normal AFV reading is 100%, but typically ranges between 90% and 110%. Much higher or lower values are possible if the map is very far off in the AFV learn domain. The higher values are found at lower altitudes /lean conditions, and the lower values at higher altitudes/rich conditions. Note that a constant correction value is applied. The system is not capable of providing variable injector duration scaling at different operating points. It is therefore only capable of raising or lowering the entire curve. It can not squash fuel peaks or raise fuel valleys in the fueling curve. The AFV is determined during a subset of closed loop operation by using the O2 sensors input, but the correction is only applied to the fuel mixture during open loop operation. This AFV compensation capability allows the DDFI system to adjust to different altitudes, air densities, and to minor modifications made to the intake or exhaust systems or other engine components. The Buell DDFI system has the ability to “learn” the engine fuel mixture needs when operating in closed loop mode. When the motorcycle is running in steady state conditions in a subset of the closed loop mode over a specific engine speed, load range, and temperatures, the system will compare the fuel injection duration calculated from the O2 sensor input to the injector duration calculated from the fuel map. This calculation is performed again and again over a period of time (This is compensated with lambda correction first and AFV in long term), and the result of these multiple calculations is averaged. The ECM uses the AFV to scale the injector durations calculated from the fuel map up or down to ensure that the proper Air/Fuel ratio is always obtained. The AFV SHOULD be a value of approximately 100%. The AFV is set by comparing the injection duration obtained from the bike when running on the O2 sensor to that obtained from the map for the same operating point. For instance, lets say that the injection duration was 9 milliseconds as obtained from the O2 sensor, but the map yields a value of 10 Millseconds. That would be a value of 9/10, or 90%. This would be the case if the bike was running at altitude in thinner air, and the 90 value would be used to scale the map dirived injection duration back so the bike doesn't run too rich. The AFV is determined during a subset of closed loop operation by using the O2 sensors input, but the correction is only applied to the fuel mixture during open loop operation. When the motorcycle is running in the closed loop mode and operated in a specific engine speed and load range, the system will compare the feedback from the O2 sensor to the base programming stored in the ECM. If a difference in these values is detected, the ECM will recalibrate the system program to compensate. This correction is termed the adaptive fuel value or AFV. Throttle rate change or changing loads will kick the system out of AFV learn mode. If the AFV is higher than normal, the system is trying to correct for a situation that would otherwise cause the mixture to be too lean. Things that can cause this are denser ambient conditions (low altitude, low temperature), less restrictive intake and/or exhaust systems, intake manifold or injector O-ring air leaks, incorrect ignition timing, incorrect TPS zero setting, low fuel pressure, or a fuel line restriction. A map that is too lean will cause the AFV to be above 100. If the AFV is lower than normal, the system is trying to correct for a situation that would otherwise cause the mixture to be too rich. High altitude, high temperature operation, incorrect ignition timing or TPS zero setting, high fuel pressure or a leaking injector are all things that can cause the AFV to be lower than normal. A map that is too rich will cause the AFV to be below 100. The Oxygen Sensor (02) is desirable to operate the engine at or near stoichiometric, or approximately 14.7 parts air to one part fuel. If usually you not change of altitude on your rides the O2 sensor doesn't matter. VERY IMPORTANT!, You must set the AFV to 100 before disable the O2 sensor. The IAT sensor: Relative Air Density; Air density effects how much oxygen is present within it. Air density is dependent on altitude (atmospheric pressure), temperature and relative humidity. Cool, dry air at lower altitudes contains more oxygen than warm, moist air at high attitudes. Hot air is less dense than cold air, Horsepower is directly related to air density. As for your question What about the default open loop correction? and what does "open loop enrich delay" do? You are right and am completely agree with you..Is this the time that the ECM takes to apply the correction in the area of the open loop fuel map and by default open loop correction is setting at 5% If you turn the O2 off then the open loop correction always it will be of 5%. Course that can be set at any value. For instance, lets say your AFV was set at 115 after ride in closed loop learning mode, then the open loop correction would be used by to scale the map a 15% in open loop. Open loop enrich delay is set at zero by default in Race X1 and at 3 in XB models. Hope Helps. Regards. (Message edited by buellisticx1 on October 31, 2009) | ||
| Dcapito |
What I'm really looking for is a conclusive answer about whether or not the ECM has a manifold air pressure input, because if it does, then the O2 sensor is redundant for atmospheric corrections (including for altitude). Unfortunately, it looks like it might not, as otherwise the ignition maps would likely be MAP instead of TPS based. Regards, Derek | ||
| Dcapito |
Well, I answered my own question by having a look at the factory service manual, which lists the various sensors the ECM uses. A manifold air pressure sensor is not among them. Very surprising and disappointing. Regards, Derek |
