Lambda sensor?

After much searching, i'm still devoid of a solid answer to what the guzzi hive mind deems to be the best setting for a G11's lambda sensor. On or off? I gather it reduces surging in some situations, but also makes the bike run leaner. I'm also still not clear how this sensor seems to cause problems, is it operating on set values that aren't adjusted with one of the maps graciously provided by beetle?

Some background: It runs much better than pre-map change, pre-pipe and pre-guzzidiag resets, but it has trouble starting when it's a bit colder outside (~0 degree C). This lack of motivation to start is eliminated right after auto learning parameters are reset, but returns after a few hours riding. Valves in check, throttle bodies not yet balanced until I track down a carbtune also.

Lambda? No lambda?

I should note as well, last plug check the plugs were looking uneven. Richer in....left cylinder if my memory serves me correctly

SuperCoyote, the Lambda tells the ECU what the "current" air/fuel ratio is, in the exhaust pretzel. This allows the ECU to trim its air/fuel ratio to ensure it is "optimum".

Having said that, it is a fairly slow device and is giving, in reality, an average reading at some point in time, not necessarily right now. Also it only works in closed loop mode, let's say below 40% throttle. For WOT applications, it is taken out of the equation.

If you have one of Beetle's maps, the Lambda will be switched off. I assume this is the case, though I cannot tell, as yet.

The whole purpose of the Lambda is to "make sure" you are running in the right conditions as deemed acceptable by the factory - this is most likely EURO 3, but I might be wrong on that (again).

As shipped, the factory map is uber rich across the range, this is corrected by the Lambda (kinda, sorta) to provide low emissions and reasonable running. It is also damn near impossible to get into a rev area where the ECU cuts fuel i.e. maximum revs as it's way too rich a mixture to get there easily.

Mark may chime in and add some light on the warm up part or what his map is configured as?

What map are you running? Stock? One of mine? 3rd party?

One of yours. GRiSO-FU2-4V-6A01.2015.02.25

Oz1200Guzzi wrote:

SuperCoyote, the Lambda tells the ECU what the "current" air/fuel ratio is, in the exhaust pretzel. This allows the ECU to trim its air/fuel ratio to ensure it is "optimum".

Having said that, it is a fairly slow device and is giving, in reality, an average reading at some point in time, not necessarily right now. Also it only works in closed loop mode, let's say below 40% throttle. For WOT applications, it is taken out of the equation.

If you have one of Beetle's maps, the Lambda will be switched off. I assume this is the case, though I cannot tell, as yet.

The whole purpose of the Lambda is to "make sure" you are running in the right conditions as deemed acceptable by the factory - this is most likely EURO 3, but I might be wrong on that (again).

As shipped, the factory map is uber rich across the range, this is corrected by the Lambda (kinda, sorta) to provide low emissions and reasonable running. It is also damn near impossible to get into a rev area where the ECU cuts fuel i.e. maximum revs as it's way too rich a mixture to get there easily.

Mark may chime in and add some light on the warm up part or what his map is configured as?

Ok, so the lambda provides feedback on whether to enrichen or lean out based on the exhaust pretzel. That helps a lot to help me understand. So if we were confident that the bike had the proper parameters to run on, we could kill the lambda and have a much more predictable fueling response throughout the rev range. Am I getting that right?

Basically yes.

The narrow band sensor is dumber than dogshit. Half a volt or no volt, with one indicating that the mixture is too rich and one indicating it's too lean, (I can't remember which offhand.) it flip-flops between one and the other constantly trimming the fuel to try and keep the exhaust content at its target which is horribly lean due to regulation.

The actual factory maps are rich but rely on this crude system to lean them out in the portions of the map that are closed loop. The tragic thing is this slavish adherence to a perceived *Good* goal actually leads to higher fuel consumption at least in part because people will try and ride around the super lean parts of the closed loop map by revving the engine higher in a lower gear or loading it up with throttle to take it out of CL.

It is really sucky on all levels and really is doing little, especially on what is basically a 'Leisure' vehicle, to preserve the environment, (Something that I am very keen on incidentally!) but it is the simplistic hand of cards we have been dealt so it's up to us to find ways around it. This does NOT involve simply flinging more fuel into the map as many self promoting snake oil salesmen will tell you. All this will do is leave you with soot all over the back of your slow, thirsty, motorbike!

Pete

supercoyote wrote:

One of yours. GRiSO-FU2-4V-6A01.2015.02.25

Right. Well lambda is 'off' in that map, so I don't get why resetting the auto-learning parameters will fix anything. The ECU is not trimming anything.

Let me make a tweak or two for better cold weather start. However, you will need to get the throttle bodies balanced, it will make a huge difference.



.

Pete Roper wrote:

Basically yes.

The narrow band sensor is dumber than dogshit. Half a volt or no volt, with one indicating that the mixture is too rich and one indicating it's too lean, (I can't remember which offhand.) it flip-flops between one and the other constantly trimming the fuel to try and keep the exhaust content at its target which is horribly lean due to regulation.

The actual factory maps are rich but rely on this crude system to lean them out in the portions of the map that are closed loop. The tragic thing is this slavish adherence to a perceived *Good* goal actually leads to higher fuel consumption at least in part because people will try and ride around the super lean parts of the closed loop map by Erving the engine higher in a lower gear or loading it up with throttle to take it out of CL.

It is really sucky on all levels and really is doing little, especially on what is basically a 'Leisure' vehicle, to preserve the environment, (Something that I am very keen on incidentally!) but it is the simplistic hand of cards we have been dealt so it's up to us to find ways around it. This does NOT involve simply flinging more fuel into the map as many self promoting snake oil salesmen will tell you. All this will do is leave you with soot all over the back of your slow, thirsty, motorbike!

Pete

I can see the advantage of turning it off then, if it can only report lean or rich conditions but in no metered fashion. So without the wideband sensor that some people talk about installing (which would still not allow fuel to be trimmed on each cylinder individually?), we're pretty much pooched for real time proper fuel trimming? I feel like i'm back in school

beetle wrote:

supercoyote wrote:

One of yours. GRiSO-FU2-4V-6A01.2015.02.25

Right. Well lambda is 'off' in that map, so I don't get why resetting the auto-learning parameters will fix anything. The ECU is not trimming anything.

Let me make a tweak or two for better cold weather start. However, you will need to get the throttle bodies balanced, it will make a huge difference.



.

Interesting. The bike seems to respond better right after a parameter reset when starting, though now that i'm typing it I did do a TPS reset at the same time. But I can't imagine cold starts and TPS sensor inputs are related? Also, in another beetle-tech related thread it was mentioned after a map change to disconnect the battery to clear....something. Might have been on guzzitech though, which I take with a grain of salt though. Resetting the ALP and disconnecting the battery for a period of time would accomplish the same thing I would assume?

Yes, disconnecting the battery or pulling the main fuses for ~1 minute will clear the volatile memory where the ALP is stored.

The TPS reset is what has caused the change. I doubt the ALP reset did anything that would make a difference. Resetting the TPS can make a noticeable difference if the throttle body sync is out.

The lambda in my GRiSO 8v gave nothing but trouble. The surging on light throttle openings was really distracting, particularly when off and on the throttle at low speeds. Created horrible driveline shunt. Got it disconnected in conjunction with a proper throttle body balance, and the bike is much better to ride. Get any slack taken out of the throttle cables too. It helps.

I really can't think of any circumstances in the real world where it's of benefit. Fuel consumption with it off is virtually unchanged to previously. Well, that's on my bike at least.

I'll have to tend to a proper throttle body balance and take that slack out then. If the low end fueling could be improved I don't know if I could be happier with a bike. Especially since finally changing the stock suspension settings, i'm getting close to GRiSO-bliss

Can't find an answer to this. I there any improvement in stock map when I only set Lambda off?

Basically turning off the lambda will make it run richer most of the time. The maps are generally very rich and rely on the narrow band sensor/s to keep pulling fuel out until they see their target AFR figures. Simply turning the lambda off is a very crude way of changing things.

Pete