Author Topic: "No-lambda" - downgrade (Read 10958 times)

Asterian · « **on:** February 11, 2013, 04:14:25 AM »

Less than at 1 year of operation (5'000 Km) my Bosch Oxygen sensor died.
First error code was - "Sensor giving wrong values", second - "Oxygen sensor failure".

After checking all electrical lines to ensure that this is no wire break etc. - I disconnected sensor.
I was quite surprised that with sensor disconnected engine runs better. Spark plugs color is Ok. Fuel consumption is approx the same like before.

So, now I wont like to come back to Lambda control.
Question 1 is - is it really necessary to put "No Lambda chip" or I can leave Lambda just disconnected and let ECU run in emergency mode?

Question 2 - In Emergency mode Motronic is using average values stored in memory.
Are this values from factory or its was stored during car operation?

romkasponka · « **Reply #1 on:** February 11, 2013, 04:54:50 AM »

It depends allot what car do you have. For e30 it could be because wrong fuel mixture was adjusted with lambda sensor unreliable data and now you have mode without lambda when fuel tables are not adjusted regarding lambda sensor. For E36 it is difficult to believe what it runs better without lambda. IMHO with operative lambda it would better anyway.

Asterian · « **Reply #2 on:** February 11, 2013, 05:02:08 AM »

Quote from: romkasponka;119992

It depends allot what car do you have. For e30 it could be because wrong fuel mixture was adjusted with lambda sensor unreliable data and now you have mode without lambda when fuel tables are not adjusted regarding lambda sensor. For E36 it is difficult to believe what it runs better without lambda. IMHO with operative lambda it would better anyway.

- Mine is E30. So.. when my Lambda started to generate wrong signal - ECU stored it and probably now car run with non adequate fuel table?

P.S. I think that price for new Lambda and No-Lambda chip are comparable. And with Lambda removing I will not afraid that at other 5000 km 100 USD will go away )) / + I don't have cat.

bmwconnect · « **Reply #3 on:** February 11, 2013, 09:09:29 AM »

Quote from: Asterian;119990

Less than at 1 year of operation (5'000 Km) my Bosch Oxygen sensor died.
First error code was - "Sensor giving wrong values", second - "Oxygen sensor failure".

After checking all electrical lines to ensure that this is no wire break etc. - I disconnected sensor.
I was quite surprised that with sensor disconnected engine runs better. Spark plugs color is Ok. Fuel consumption is approx the same like before.

So, now I wont like to come back to Lambda control.
Question 1 is - is it really necessary to put "No Lambda chip" or I can leave Lambda just disconnected and let ECU run in emergency mode?

Question 2 - In Emergency mode Motronic is using average values stored in memory.
Are this values from factory or its was stored during car operation?

1. You can leave it disconnected and with a non functioning O2 sensor the DME does not run in Limpmode or Emergency mode. The sensor is not that important to operation.

2. The DME calculation for fuel injections works like this... Kfaktor > AFM table> Injection correction table (stored value's) > O2 Sensor . The O2 sensor is there for fuel economy and to warn you of possible failures with the fuel injection system such as a injector getting slow.

romkasponka · « **Reply #4 on:** February 11, 2013, 10:34:06 AM »

Why do you think the O2 sensor is for fuel economy? It is for proper fuel/air mixture, but it does not mean only economy.

bmwconnect · « **Reply #5 on:** February 11, 2013, 11:01:09 AM »

Quote from: romkasponka;120008

Why do you think the O2 sensor is for fuel economy? It is for proper fuel/air mixture, but it does not mean only economy.

Fuel economy = proper fuel air mixture. It also functions to keep the KAT working correctly and in it's temperature range. It also serves as a diagnose tool

doitover · « **Reply #6 on:** February 11, 2013, 01:07:39 PM »

I believe most, if not all, computers with a narrow band O2 sensor use it only for closed loop operation. For WOT, the O2 sensor isn't used. That's where your dyno numbers come from.

romkasponka · « **Reply #7 on:** February 11, 2013, 05:29:52 PM »

Quote from: doitover;120011

I believe most, if not all, computers with a narrow band O2 sensor use it only for closed loop operation. For WOT, the O2 sensor isn't used. That's where your dyno numbers come from.

My E30 m42 and E36 m44 with dead lamda sensors had difference in performance. E30 with dead lambda was not willing to rev higher than 3000rpm after 1 minute when cold engine was started... I have no live data experience with diagnostic on E30, but on E36 for sure there there is adaptations which are corrected by lambda sensor and later they influence all the rev range. See attachements....

bmwconnect · « **Reply #8 on:** February 11, 2013, 09:20:11 PM »

Quote from: romkasponka;120016

My E30 m42 and E36 m44 with dead lamda sensors had difference in performance. E30 with dead lambda was not willing to rev higher than 3000rpm after 1 minute when cold engine was started... I have no live data experience with diagnostic on E30, but on E36 for sure there there is adaptations which are corrected by lambda sensor and later they influence all the rev range. See attachements....

Big difference in operation between OBD1 E36 M42 and OBD2 E36 M44? which are we talking about? E36 M42 can run fine without O2 sensor but will be on the rich side around 13.5 while cruising .

romkasponka · « **Reply #9 on:** February 12, 2013, 12:29:59 AM »

Quote from: bmwconnect;120022

Big difference in operation between OBD1 E36 M42 and OBD2 E36 M44? which are we talking about? E36 M42 can run fine without O2 sensor but will be on the rich side around 13.5 while cruising .

E36 m44 I can say 100% because I own one. Other I do not know. But in any case even for E30 m42 M1.7 they say: DME performs the folowing operations - adaptive oxygen sensor regulation. It means DME fine tune mixture regarding oxygen sensor measurements. Some guys say there is no difference with or without lambda, but probably you will not feel small difference sometimes and depends how close fuel mixture is from optimal mixture with lambda adaptations.

I am not DME guru but in all cases my cars (E30 m42 and E36 m44) was running much better with lambda sensor. In E30 case I had no possibility to read DME data so just pedal test was done by me.

Quite often lambda sensors are damaged during installation because thread was rusted and by forcing new lambda in to rusted thread you just make ceramics inside to crack. You must clean thread and tighten lambda just few Nm avoiding overtorque.

Asterian · « **Reply #10 on:** February 12, 2013, 02:27:54 AM »

How long DME stores "adaptive oxygen sensor values" in memory? I.e., will it still be there after battery disconnected for relatively long time? Have this values used by DME for correction after DME detects that lambda is non-operative?

romkasponka · « **Reply #11 on:** February 12, 2013, 03:23:50 AM »

I do not have answers to your questions. For m44 you have special command using INPA to reset adaptation values.

bmwconnect · « **Reply #12 on:** February 12, 2013, 09:53:12 AM »

Quote from: Asterian;120032

How long DME stores "adaptive oxygen sensor values" in memory? I.e., will it still be there after battery disconnected for relatively long time? Have this values used by DME for correction after DME detects that lambda is non-operative?

For OBD1 they are reset after battery is unplugged.

blueboi69 · « **Reply #13 on:** February 17, 2013, 05:14:37 AM »

Hi,

My e30 m42 can't run without o2 sensor. Idle stalls and it has no power while driving. That's my experience with it.

Asterian · « **Reply #14 on:** April 08, 2013, 07:18:11 AM »

Ok, closing issue.. running without lambda for 3-rd month already. Driveability still same like before and with sensor.

Question - what can be cause of that fact that without Lambda idle is more smooth that with?