| Author | Message | ||
     Paolo |
Argh, topics are just drowned in KV...  <copy> Whats the expected ECM behavior if I unplug the O2 sensor? Does the ECM return immediately to open loop mode, if it gets bad data (error) from a sensor in closed loop mode? The purpose of this is to make the ECM use my Directlink-tuned maps all the time, instead of getting input from sensors. We don't have much variation in heights here where I live, so the O2 sensor isn't really necessary for me... : ) | ||
| Firebolteric_ma |
Ummmm...you may want to look into this further. Call up AL for a REAL detailed answer. You say:...."We don't have much variation in heights here where I live, so the O2 sensor isn't really necessary for me... : )" Does the humidity level change at all? does the air temperature change? does you right wrist twist the grip? YES you need the o2 sensor... yes you bike will use the map you put in it. what else would it use? even with the sensors it still is used. is there something you are trying to accomplish here? the only reason i would disconnect it is to do a test procedure OR to do a few mods to the map using Al's "beta system" for some fine tunning of the map. | ||
| Xb9 |
"Whats the expected ECM behavior if I unplug the O2 sensor?" The ECM will use the maps (open loop), and eventually set a trouble code when it tries to learn. When tuning mine on the street with the O2 sensor to the ECM disconnected, there was a stumble for a second as the code was set and the engine light comes on, then it runs fine (off the maps). This would occur during steady throttle & RPM (cruise) in the AFV learning region of the map. "Does the ECM return immediately to open loop mode, if it gets bad data (error) from a sensor in closed loop mode." Yes, in regards to the O2 sensor; don't know about the other sensors. You could run without an O2 sensor, it would be no worse than a carb. If you don't mind the stumble and the engine light coming on!  | ||
| Fullpower |
i have moved the O2 sensor connector to the area below my right thigh, so that i can disconnect the O2 sensor lead while riding. I have not noticed any difference in the behavior of the bike after disconnecting the O2 sensor. I did once have the check engine lamp illuminate, but only once. | ||
| Paolo |
Thanks for the answers! -- -- -- Firebolteric_ma : "yes you bike will use the map you put in it. what else would it use? even with the sensors it still is used." Yes, but in closed loop mode it seems to "correct" the map values (AFV) to obtain near stoichimetric a/f ratio, and thats not what I want. "is there something you are trying to accomplish here?" Yes, targetting to constant 13:1!  -- -- -- Xb9: "Yes, in regards to the O2 sensor; don't know about the other sensors. You could run without an O2 sensor, it would be no worse than a carb. If you don't mind the stumble and the engine light coming on!" Thanks, this is just what I looked for! -- -- -- Fullpower: "i have moved the O2 sensor connector to the area below my right thigh, so that i can disconnect the O2 sensor lead while riding." Good idea. -- -- -- | ||
| Martin |
I fitted a switch in the wire and mounted it in the black plastic infill panel between the cylinders. My engine check light comes on as soon as I cruise when the switch is 'off' and a constant motorway cruise at 80mph for 30 miles in that state fouled or melted the plugs. | ||
| Paolo |
Martin: ...and a constant motorway cruise at 80mph for 30 miles in that state fouled or melted the plugs. Whoa, thats not good!  What a/f ratio your maps are targeted, approximately? What other modifications your bike has? Race or stock ECM? | ||
| Firebolteric_ma |
Now that I can see happening. With the air temp/humitity constantly changing and the bike can not accomodate(SP?) these conditions bad things are going/could happen. You can not compare a carb to fuel injection. You may get away with this for short periods of time but i think eventually it will catch up with you. Are you running Direct Link for this? | ||
| Xb9 |
If you're going to try and run w/o the O2 sensor, you best make sure you're maps are correct beforehand. I would never do it without being positively sure I had accurate mapping in the ECM for that particular bike. You can only be sure the maps are accurate with a dyno or a wideband 02 controller. But even then I would not recommend running without the O2 sensor on a permanent basis for street use. That most likely was Martin's problem - I'll speculate he was running stock maps on a bike with some mods? Also with the switch "on" the O2 sensor creates a millivolt (0-1V) signal to the ECM that may easily become skewed if additional resistance (a switch) is introduced in the O2 circuit wiring. Once my bike was mapped accurately with DL using a wideband O2 controller, I can run it all day long w/o the O2 sensor connected. The light will come on and stumble for a second if you cruise and it tries to learn, but it runs fine. I've done this while monitoring the Air/Fuel value realtime on a Palm connected to the wideband controller. After the light comes on the ECM realizes that there is no O2 sensor signal and falls back on just using the fuel maps. After mapping, my AFV stays at 100 (with the O2 sensor functioning) so I'm sure the cruise or learn area of the maps are very near perfectly tuned to 14.7:1. Without the O2 sensor, the ECM should still adjust for air and engine temperature (Intake Air Temp Sensor, Engine Head Temperature), but it cannot adjust for altitude or Baro (air density - O2 sensor) I still think you'd be better off to rethink your desire to run the bike at 13:1 everywhere in the TPS/RPM range for street use, exception is racing. These ECM's really need to be tuned to different air/fuel ratios in different regions of the map, Al at American sportbike has the best handle on how it needs to be done with his tuning guide that comes with DL if you buy it through him. | ||
| U4euh |
Xb9, sent you a PM! | ||
| Martin |
absolutely spot on, XB. I lent the bike to a mate to 'pop up to the shop to see how they were doing with his bike' I guess he started enjoying himself. The bike had a standard map in but some filter and exhaust mods. |
