When does the ECM switch from closed loop to open loop mode?

[khollister]

Doc,

I'm not sure I'm following you on the reduced life of the O2 sensor. The voltage divider lowers the output voltage of the sensor, I thought, so I do not understand how that can affect the sensor itself. These are 2-wire sensors with no heater as far as I know. There is no sensor bias as far as supplying voltage to set a sensor operating point that I know of. You obviously have a lot more experience in this than I do, but my brain can't grasp how using a voltage divider to drop the output voltage is going to affect the sensor itself.

I'm clearly missing something - can you clarify this? Or maybe I totally misunderstood what you were saying.

Keith

[HDMD88]

Originally Posted by claydbal

doc, you knowv i espect you and your answers are un debateable. i have tio ask--if a sensor is off and closed loop depends on that false info, wouldnt the ecm feed eronious info? maybe the factory o2 sensor senses a rich mix and leans to compensate-------------equals fried piston?

Not quiet sure what your asking me Dennis so I hope this answers your question. The 02 sensor only has the ability to switch the AFR by .5 so if it was set with the Bias voltage t otarget 14.1:1 AFR and the sensor went bad (not signaling the ECM) the AFR would go to the setting that was programed in the AFR table which is 14.6:1. The bike will run at this AFR but it will be a little hotter than the 250 running degrees you are seeing now on a hot day. Keep in mind Harley says there is no problem until you reach 300*

[HDMD88]

Originally Posted by Bingo

More confusion.

I read so many posts that recommended the clb table be maxed out at .798 so that's what I did to my 08 RG.

This is not a good thing? So I really don't know how to richen the mix for a SE air cleaner and true dual's?

Sorry I don't want to confuse you all...it's simple, the 02 sensor operates on a 0 volt to 1 volt current, .45~.48 volts is in the middle of that voltage and that Bias Voltage reports to the ECM and the ECM is programed to know what AFR relates with the voltage it reads and the ECM sends it out to the injectors. At .45v ~.48v it sees a AFR of 14.67:1, setting the voltage to .55 would deliver 14.5:1.....voltage of .60 would give about 14.4:1 AFR. A maxed out voltage of .798 will deliver 14.2:1 ~ 14.1:1. I do this too so the bike will run cooler.....all I'm saying is the bottom line...your looking for 14.1 for your AFR why not just set the AFR table at 14.1 and don't worry about the closed loop operation.
The 02 is a switching device....it switch's from 0 volts to 1 volt...if you set the Bias Voltage to .798 (like we all do) the 02 sensor is at the edge of its switch or learning ability using more voltage all the time which starts to shorten it's life .Once the sensor dies the AFR goes to the programed 14.6 it sees in the AFR table. This might take 6000 to 10,000 miles to happen, problem is it will happen. Again to be safe just program the 14.1:1 in the AFR Table and be done with it.....bike runs cooler and the 02's are off line.

This has nothing to do with how much oxygen is in the pipe....it's all voltage.

[claydbal]

Originally Posted by HDMD88

Not quiet sure what your asking me Dennis so I hope this answers your question. The 02 sensor only has the ability to switch the AFR by .5 so if it was set with the Bias voltage t otarget 14.1:1 AFR and the sensor went bad (not signaling the ECM) the AFR would go to the setting that was programed in the AFR table which is 14.6:1. The bike will run at this AFR but it will be a little hotter than the 250 running degrees you are seeing now on a hot day. Keep in mind Harley says there is no problem until you reach 300*

yep, you answered the question. so sensor failure forces ecm to maintain stoich, which is safe enough to get home without damage.

thanks doc.

[BVBOB]

Originally Posted by HDMD88

Sorry I don't want to confuse you all...it's simple, the 02 sensor operates on a 0 volt to 1 volt current, .45~.48 volts is in the middle of that voltage and that Bias Voltage reports to the ECM and the ECM is programed to know what AFR relates with the voltage it reads and the ECM sends it out to the injectors. At .45v ~.48v it sees a AFR of 14.67:1, setting the voltage to .55 would deliver 14.5:1.....voltage of .60 would give about 14.4:1 AFR. A maxed out voltage of .798 will deliver 14.2:1 ~ 14.1:1. I do this too so the bike will run cooler.....all I'm saying is the bottom line...your looking for 14.1 for your AFR why not just set the AFR table at 14.1 and don't worry about the closed loop operation.
The 02 is a switching device....it switch's from 0 volts to 1 volt...if you set the Bias Voltage to .798 (like we all do) the 02 sensor is at the edge of its switch or learning ability using more voltage all the time which starts to shorten it's life .Once the sensor dies the AFR goes to the programed 14.6 it sees in the AFR table. This might take 6000 to 10,000 miles to happen, problem is it will happen. Again to be safe just program the 14.1:1 in the AFR Table and be done with it.....bike runs cooler and the 02's are off line.

This has nothing to do with how much oxygen is in the pipe....it's all voltage.

So Doc, if I read this correctly, you are basically saying to just eliminate the 02 sensors feedback and operation by taking the bike out of closed loop(by programming 14.1:1 in afr table)?, I know we have discussed this before and you know how I feel about the factory 02 system, but I thought you were against eliminating their operation. The failure of the 02 sensors has been one of my concerns since this system first came out, I have seen far too many failures of the 02's on auto's for me have complete faith in them.

[HDMD88]

Originally Posted by BVBOB

So Doc, if I read this correctly, you are basically saying to just eliminate the 02 sensors feedback and operation by taking the bike out of closed loop(by programming 14.1:1 in afr table)?, I know we have discussed this before and you know how I feel about the factory 02 system, but I thought you were against eliminating their operation. The failure of the 02 sensors has been one of my concerns since this system first came out, I have seen far too many failures of the 02's on auto's for me have complete faith in them.

It's all in what you want Bob....if you program in 14.1 you know you'll get it IF your VE's are right. I like the operation of the 02s cause it makes up for slight deviations (mistakes) in the VE's plus the Adaptive Fuel Values. I have learned more about all this as time has gone by, one of those lessons was the premature failure of the 02 (switching device) when maxed out to it's limit, but then again 10,000 miles is a long way.....I will continue to do what I have done in the past for people who want the 02's and want the cooler running bike also.

[kslg]

Speaking of adaptive fuel- If I add an intake kit- would it add enough fuel to keep the closed loop at 14.7/14.2 (with the hd download to handle the open loop)?

I think you said previously that it can only add 10%?

And- When are you going to change your user ID to HDMD96o2?

[HDMD88]

Originally Posted by kslg

Speaking of adaptive fuel- If I add an intake kit- would it add enough fuel to keep the closed loop at 14.7/14.2 (with the hd download to handle the open loop)?

I think you said previously that it can only add 10%?

And- When are you going to change your user ID to HDMD96o2?

You have to understand the down load richen the fuel all the way from the 0% to 100% in the map even though the closed loop is still at 14.6. The down load tells the ECM it has higher VE's, in other words, it tells the ECM it has a bigger engine more air flow so it's like having a qt jar filled with a ratio of 14.6 vs a gallon jar filled to a ratio of 14.6.....which one do you thing has more fuel even though th ratio's are the same.

Having the 88 on HDMD shows my age doesn't it....I thought about changing it to 96 but you know as well as I do that it will go to 103 then 113 then to 117 on and on and on.....lol lol lol

[Bingo]

Originally Posted by HDMD88

Sorry I don't want to confuse you all...it's simple, the 02 sensor operates on a 0 volt to 1 volt current, .45~.48 volts is in the middle of that voltage and that Bias Voltage reports to the ECM and the ECM is programed to know what AFR relates with the voltage it reads and the ECM sends it out to the injectors. At .45v ~.48v it sees a AFR of 14.67:1, setting the voltage to .55 would deliver 14.5:1.....voltage of .60 would give about 14.4:1 AFR. A maxed out voltage of .798 will deliver 14.2:1 ~ 14.1:1. I do this too so the bike will run cooler.....all I'm saying is the bottom line...your looking for 14.1 for your AFR why not just set the AFR table at 14.1 and don't worry about the closed loop operation.
The 02 is a switching device....it switch's from 0 volts to 1 volt...if you set the Bias Voltage to .798 (like we all do) the 02 sensor is at the edge of its switch or learning ability using more voltage all the time which starts to shorten it's life .Once the sensor dies the AFR goes to the programed 14.6 it sees in the AFR table. This might take 6000 to 10,000 miles to happen, problem is it will happen. Again to be safe just program the 14.1:1 in the AFR Table and be done with it.....bike runs cooler and the 02's are off line.

This has nothing to do with how much oxygen is in the pipe....it's all voltage.

Thanks, Doc. I do appreciate the help, and I am slowly learning!

So I put the clb back to it's original setting. I lowered the afr to 14.1, but now I understand that takes the o2's off line (?).

So could I not go to the VE tables for front and rear and bump them up a few (guessing) points? Would this not keep the o2's in line, but richen the mixture as well?

Seems to be difficult to get the best of both worlds here. I slightly modified the breather (SE) and exhaust, but I don't want to have the bike self destruct components, as I do plan on putting lots of K's on. I ran the 02 Standard for 90,000 K (over 50,000 miles) and plan on even more for the RG.

Thanks again, Doc!

[airmann6]

Whew, I need to take a breath , all I know is with Oval Sips ons , Big Sucker and IED wires my 08 FLHX runs and sounds great with no signs of being lean . (so far)

[Paul Goodfield]

Originally Posted by Bingo

Thanks, Doc. I do appreciate the help, and I am slowly learning!

So I put the clb back to it's original setting. I lowered the afr to 14.1, but now I understand that takes the o2's off line (?).

So could I not go to the VE tables for front and rear and bump them up a few (guessing) points? Would this not keep the o2's in line, but richen the mixture as well?

Seems to be difficult to get the best of both worlds here. I slightly modified the breather (SE) and exhaust, but I don't want to have the bike self destruct components, as I do plan on putting lots of K's on. I ran the 02 Standard for 90,000 K (over 50,000 miles) and plan on even more for the RG.

Thanks again, Doc!

Ive' always wondered about the possibily of the above and if there was anyway of knowing what percentage to simply increase the VE or Cubic Inch area to acheive a richer AFR without stressin' out the sensors. Would seem to be the best of all worlds, no stress on the sensors and stay in closed loop to boot? No?

I awaited with baited breathe as I read the above thread but it ended with one other response after that did not address the question. A chart would be a dream come true!

Any experts?

[strokerjlk]

Originally Posted by Paul Goodfield

Ive' always wondered about the possibily of the above and if there was anyway of knowing what percentage to simply increase the VE or Cubic Inch area to acheive a richer AFR without stressin' out the sensors. Would seem to be the best of all worlds, no stress on the sensors and stay in closed loop to boot? No?

I awaited with baited breathe as I read the above thread but it ended with one other response after that did not address the question. A chart would be a dream come true!

Any experts?

I too would love it if Doc would join back in!!!
Because I have a lot of questions also!

[ToBeFrank]

Originally Posted by Paul Goodfield

Ive' always wondered about the possibily of the above and if there was anyway of knowing what percentage to simply increase the VE or Cubic Inch area to acheive a richer AFR without stressin' out the sensors. Would seem to be the best of all worlds, no stress on the sensors and stay in closed loop to boot? No?

If the AFR table is set for closed loop (14.6), the O2s are controlling the AFR. Increasing the VE table will result in the O2s correcting it back to where it was. The only way to richen the AFR when in closed loop is to use the CLB table. If you want to richen it with the VE table, you have to take it out of closed loop.

[strokerjlk]

Originally Posted by ToBeFrank

If the AFR table is set for closed loop (14.6), the O2s are controlling the AFR. Increasing the VE table will result in the O2s correcting it back to where it was. The only way to richen the AFR when in closed loop is to use the CLB table. If you want to richen it with the VE table, you have to take it out of closed loop.

I am going to disagree and agree with ya.
you are correct in you statement with the exception of......
You can run in closed loop with a AFR of your choosing .
example: take it out of closed loop to say 13.4 and adjust ve to achieve 13.4 actual. Then when you take it back to closed loop by changing numbers to 14.6 it is actually running at 13.4 (+or - .5 according to what bias is set at) you have tricked the ecm and are now running in closed loop at 13.4 instead or 14.6.
Doc correct me if I am wrong or enlighten me if I missed something . I have several questions myself on data logging.
THANKS

[Paul Goodfield]

Originally Posted by strokerjlk

I am going to disagree and agree with ya.
you are correct in you statement with the exception of......
You can run in closed loop with a AFR of your choosing .
example: take it out of closed loop to say 13.4 and adjust ve to achieve 13.4 actual. Then when you take it back to closed loop by changing numbers to 14.6 it is actually running at 13.4 (+or - .5 according to what bias is set at) you have tricked the ecm and are now running in closed loop at 13.4 instead or 14.6.
Doc correct me if I am wrong or enlighten me if I missed something . I have several questions myself on data logging.
THANKS

Maybe we can get Steve Cole to weight in on this.