R1100RS not a surging question

[rkjjeep]

Like many of you I have probably read every thread on surging but I bought another 1999 R1100RS anyway. These bikes pull you in.
My question is - given the configuration I received the bike in what fueling was the motronic likely doing:

O2 sensor connected.
Dobeck R259 installed and pots set to baseline (LEDs were lighting)
Cat Code Plug Removed
No POT installed
Prev owner had done the original Lentini zero - zero

It ran good but the idle was around 1250 warm. I plan on a "new" 250mv zero = zero and probably a go with the techlusion or a try of the AF-XIED. I'm just curious about what the motronic was doing in the received config. Thanks.

 

[PGlaves]

Like many of you I have probably read every thread on surging but I bought another 1999 R1100RS anyway. These bikes pull you in.
My question is - given the configuration I received the bike in what fueling was the motronic likely doing:

O2 sensor connected.
Dobeck R259 installed and pots set to baseline (LEDs were lighting)
Cat Code Plug Removed
No POT installed
Prev owner had done the original Lentini zero - zero

It ran good but the idle was around 1250 warm. I plan on a "new" 250mv zero = zero and probably a go with the techlusion or a try of the AF-XIED. I'm just curious about what the motronic was doing in the received config. Thanks.

Roger04RT to the white courtesy phone please.

 

[rkjjeep]

Thanks Paul. I don't want to derail the thread but I should have added some background. This is my fifth R1100 and one of over 100 motorcycles I've owned (including 30 or so airheads) during 50 years of riding. I've been through the "try to make the oilhead run right" thing many times and am pleased to come back and see some new info from Roger and others. This shows as my first post since I couldn't figure out how to renew my long term but expired MOA membership. I am not as OCD as others and I'm happy with a bike that runs good even with a few minor annoyances. I was just trying to define how my bike was thinking as received as described above.

 

[roger 04 rt]

I don’t know for sure how much the Techlusion is adding to richness, so I’ll ignore it in the first pass. Happy Wanderer plotted the fueling using an LC-1 and the chart is in my long thread. (https://forums.bmwmoa.org/showthread.php?56990-2004-R1150RT-Wideband-O2-Sensors/page15)

With no Coding Plug installed, the O2 sensor was being ignored. Assuming you run fuel with 10% ethanol, and based on HW’s measurements (below): your too rich at idle (11.8-12.4:1), comfortably rich at low speeds (about 13.8:1 which is 6% rich) and slightly leaner than stock at highway speeds. The Techlusion on low settings is probably adding a bit of fuel to that.

You can fix the idle richness with either a CO POT or scraping the Techlusion, adding a coding plug and an AF-XIED (and if your O2 sensor is really old it may need to be replaced). The AF-XIED with give you nicely rich across the board since the Motronic will be using Closed Loop and the O2 to regulate fueling.

The old Lentini z=z didn’t affect fueling, it just left the throttle butterflies opened a bit too much.

 

[rkjjeep]

Thanks Roger, and the bike ran pretty much as the fuel plot would predict. Super rich smelling idle, little to no surge and I didn't really get it to highway cruising. As I mentioned before I am super appreciative of the new knowledge available now since I last owned one of these. My plan is to use the new idle throttle plate and TPS setting procedure, see if the Dobeck can make it good enough, and if not swap to the AF-XIED. The prev owner did install a new O2 sensor fairly recently. I'll obviously leave the CCP in as I really want the bike to run closed loop. Those Bosch guys bought me a lot of beers back in the day. I'm not looking for absolute perfection like I used to............now I am satisfied with good enough to enjoy riding the bike. Thanks again.

 

[happy wanderer]

The problem with the Dobeck device and others like the Booster Plug is that while they do enrich the mixture the effects are temporary. This is because the O2 sensor voltage informs the ECU about the new found richness and the ECU "learns" it's way back to where it wants to be; 14.7/1 AFR.

The AF-XIED works because it sits in between the O2 sensor and the ECU. It sees the O2 sensor voltage and then increases or decreases it to reach a setting of your choosing. So it sends the ECU a modified voltage reading that makes it think your AFR is fine when in fact it is richer.

I currently run my '00 1199RT at 13.8/1 AFR. It has two output channels so I use a fixed switch on my handlebars to switch between 13.8/1 in the city and riding through towns with a lot of stop lights. I switch to 14.2/1 on the highway where surging is not as noticeable at speed which save me a bit of fuel on long rides. My LC-1 fuel controller is what the AF-XIED is based on but the AF-XIED has fixed set points while the LC-1 let me do just about anything and also it logs real time data. This came in very handy in the early days of Roger's research into this issue. He then worked with Innovate Motorsports and now we have the AF-XIED for both oilheads and newer BMWs.

Long story short; I would pass on the Dobeck box and just install the AF-XIED if you have surging issues.

 

[jsouth]

The problem with the Dobeck device and others like the Booster Plug is that while they do enrich the mixture the effects are temporary. This is because the O2 sensor voltage informs the ECU about the new found richness and the ECU "learns" it's way back to where it wants to be; 14.7/1 AFR.

Is this true even on the 1100 oilheads? I didn't think they "learned."

 

[happy wanderer]

Is this true even on the 1100 oilheads? I didn't think they "learned."

They do. Roger04RT is the expert on AFR and the surging issue with oilheads. I ran quite a few test runs with various configurations using variables Roger wanted and then sent him all the logs. His posts on this issue are all on this forum, ADVRider and other forums. In those logs and with Roger's expert analysis it is quite obvious the effects of the ECU learning out the fuel trims artificially introduced by widening the injector pulses or trying to spoof the air temp sensor into making the ECU think it is very cold out so it should go deeper into the fuel map and run richer till things warm up are simply learned out and adapted to in fairly short order.

To get back to how great it felt on day one of these device installations you would need to constantly reset your ECU by pulling it's power fuse for a good long time and then it starts from a base line and learns from there again. And again. And again... The AF-XIED provides a constant modified voltage signal to the ECU that makes it think the mixture is too lean so it richens it constantly as well. Doing it this way negates the possibility of learning out the richer mixture which is what all but eliminates the surging.

 

[roger 04 rt]

Is this true even on the 1100 oilheads? I didn't think they "learned."

What HW said is right but I would add that it’s possible to keep them from learning by removing the coding plug. However if you have an O2 and a Coding Plug they do develop learned fuel trims.

 

[rkjjeep]

OK thanks for all the input and I don't want to re-open an old debate. If both the dobeck and the AF-XIED are "between" the O2 and ECU why does the motronic learn and eventually negate the effects of the dobeck but not the XIED? I love the simplicity of the XIED and will likeley go that direction - just trying to understand why one is "temporary" and the other is not. Thanks.

 

[roger 04 rt]

OK thanks for all the input and I don't want to re-open an old debate. If both the dobeck and the AF-XIED are "between" the O2 and ECU why does the motronic learn and eventually negate the effects of the dobeck but not the XIED? I love the simplicity of the XIED and will likeley go that direction - just trying to understand why one is "temporary" and the other is not. Thanks.

The Techlusion and AF-XIED work differently. The Techlusion works by monitoring the frequency and pulse width of the signal to the fuel injectors, and then lengthening that signal. In order to keep the lengthening from being “learned” away, the O2 is disconnected except at idle. So in the Tech’s only purpose for an O2 connection is to disable it and disable Closed Loop, preventing learning.

By contrast, the AF-XIED works by measuring the O2 sensor and computing a modified signal that it sends to the ECU. The ECU then calculates and “learns” new richer fueling values by taking advantage of the Closed Loop function.

 

[rkjjeep]

I am less and more confused at the same time. The R259 sits between the motronic and the O2 sensor so that it can prohibit closed loop under most conditions and just add a little fuel to improve things based on monitoring at the injector connection? If the motronic isn't seeing the O2 sensor what type of map does it default to that the R259 then adds fuel to?

I think i understand how the XIED works. The R259 - not so much.

And now I can't find an XIED in stock.

 

[roger 04 rt]

I am less and more confused at the same time. The R259 sits between the motronic and the O2 sensor so that it can prohibit closed loop under most conditions and just add a little fuel to improve things based on monitoring at the injector connection?

That's correct although some Dobeck units just disconnect the O2 entirely. In any case it determines RPM and Engine Load by monitoring the rate and pulse width of the injector pulse, and then extends the pulse about. Clever, but two downsides: when you coast with the throttle completely shut, there is no signal at the injector so the Dobeck has to recapture rate and width to start working again; and there is no closed loop adaptation to changes in your motorcycle's hardware.

If the motronic isn't seeing the O2 sensor what type of map does it default to that the R259 then adds fuel to?

I think i understand how the XIED works. The R259 - not so much.

And now I can't find an XIED in stock.

The MAP is always the one specified by the particular coding plug. It's a default map at approximately 14.7:1 and assumes pure gas, so it's a bit lean for E10 fuel.

 

[rkjjeep]

Thanks! I think I understand now. I really like the idea of the system that keeps the closed loop capability but at a more fun to ride A/F ratio.

 

[rkjjeep]

OK my new O2 sensor is here and I wll probably install the XIED this weekend. I've read that some have combined the booster plug with XIED. The prev owner gave me a booster plug in a box. What is the story about how these two devices work together. thanks