My car eats Lambda sensors

[jtbo]

http://www.janiervast.com/projekti/kuvat/ms/lambda/

Two sensors probably broken, only 3000km driven I can't afford buying lambda sensor each month.

Currently installed lambda does this:

After start, lambda does warm up and suddenly goes above 1Volt and then faints to 0, when I switch off engine and wait around 15 minutes it works similar way again.

Previous lambda started to show constant rich mixture, after I fit this new one it did read mixture properly, but when I did one overtake this new lambda stopped working.

I don't know lot of these sensors but I know that is is practically impossible to connect wrong. I have even wired extra ground to exhaust, so that can't be problem either.

I have removed and installed again this lambda, I have tried cleaning it, but always it works similar way

Position of lambda sensor is very similar that B200F has, so I think that should not be a problem.

Any ideas coming, even crazy ideas?

Thank you from help

[pettaw]

I don't know much about Lambda sensors, but I've been reading a lot about them as I'm about to megasquirt my B200. Jani is yours a heated O2 sensor. Apparently these are less prone to breakdown than the non heated ones. Also orientation of the sensor is apparently extremely important. Ideal position is between 10 o'clock and 2 o'clock, but they mustn't be lower than horizontal.

[classicswede]

My lambda is slighty lower than horizontal and is working well so far.
As Andy asked is it a heated lambda 3 or 4 wire. I have found that second hand 400 ones work well. The other thing to look out for is if you used a universal probe were the conections silver soldered as the wire is stainless
steal.


Dai

[jtbo]

My sensor is heated one and it is indeed in horizontal, same way as in b200f has according to V****-software.

[foggyjames]

Is this a wideband, or a narrowband? As Andy said, is it heated? If it's a wideband, which controller are you using?

The manufacturers say positioning below horizontal increases the chances of failure due to condensation accumulating in the lower half of the pipe.

Assuming it's a heated wideband and you've got it wired up correctly, the most likely thing by far is that you're killing it by running far too rich, especially since it failed during an overtaking manouver (sp?).

cheers

James

[foggyjames]

Looking at those graphs, it looks like the output of a wideband, but one which is going from extremes of rich to extremes of lean very quickly. Were these full-throttle pulls?

cheers

James

[jtbo]

It is narrowband, heated one.

You can see map value in graphs too, 100 is fully open throttle, idle around 40-50. some graphs are from idling, some little revving when standing still and some when driving. I can see from early log files that O2 has been normal.

This current sensor (2nd) is just driving me crazy as it looks like to be sensing changes until it reaches certain temperature, also it goes above 1 Volts that should not be possible.

But this weird activity indeed started when I overtook few cars, mixture was around 13.5:1 by then, after touching limiter in 3rd lambda wen't crazy few times it flashed proper reading and after that it has been like it is now, works like new until it reaches certain temperature.

I'm hoping to get B200F exhaust manifold as I have heard that it has lambda plug in it?

Then I buy new lambda and hopefully these problems will disappear.

Car runs fine, but I have just no idea about what kind of mixture it is burning, fuel is expensive, but so is lambda sensors too

I guess that there is no way to wake up this lambda sensor anymore?

I did try cleaning it with CRC, but only thing it did is that lambda looks clean, still works same way, very badly.

[foggyjames]

Have you calibrated the output? You know a narrowband physically cannot tell you you're running 13.5? It can only say whether you're above or below 14.7...hence why they're pretty useless as a diagnostic tool.

cheers

James

[jtbo]

Have you calibrated the output? You know a narrowband physically cannot tell you you're running 13.5? It can only say whether you're above or below 14.7...hence why they're pretty useless as a diagnostic tool.

cheers

James

That was reading in my mixture meter, it was not full rich as it can go if I adjust fuel mapping.

Sure narrowband is not most precise but still it is possible to use it to get near 14.7:1 mixture.

Here is graphs from other car:
http://www.kolumbus.fi/janne.kaivola/Images/log_2.jpg
http://www.kolumbus.fi/janne.kaivola/Images/log.jpg

With narrowband it is quite impossible to use logs to read mixture, you need either mixture gauge or something like that, logged graph just shows how sensor data goes up and down rapidly.
There is many guys who have adjusted their fuel map with narrowband and when they plug in wide band there has not been much to adjust.

In megatune software ther is this mixture display and there I can read also how rich or lean I run.

I don't know if mixture was 13.5 or 14.0, but It was not lean and not as rich as in cold start. In cold start I got almost all 10 leds illuminated, when driving usually there was only one or two flashing, first led is 14.3:1 if I remember correctly, I don't have better mixture gauge yet.

First I was thinking that maybe it was megasquirt that did broke my lambda so this second lambda was not as often attached to megasquirt, but it was attached to my mixture gauge.

[foggyjames]

I think get that thing on a wideband and you'll find out that it was running pig-rich, and that toasted the probe. They're not devices which are inherantly prone to failure, and there are only so many ways in which they can fail.

Out of interest, how much did you let it heat up before starting the car?

cheers

James

[jtbo]

I think get that thing on a wideband and you'll find out that it was running pig-rich, and that toasted the probe. They're not devices which are inherantly prone to failure, and there are only so many ways in which they can fail.

Out of interest, how much did you let it heat up before starting the car?

cheers

James

I did not let it heat at all before starting my car.

I'm just not sure about that rich thing as engine will start to run poorly if I lean mixture even a bit, that is case in most of map, higher loads are probably bit rich, but I think that safer that way.

Can't afford wideband, specially not now as I need to move, change job and try to keep car running

I'm counting every cent currently so could be that my tuning is to be done with arse quite long to future. Maybe I can find lambda and exhaust manifold for 30 euros, then tuning would be bit easier.

[foggyjames]

Why not just pull a lambda probe from any Volvo?

cheers

James

[jtbo]

Why not just pull a lambda probe from any Volvo?

cheers

James

This garage (car repair shop?) that did install that knob to exhaust pipe did very bad job, threads were destroyed and therefore this 2nd lambda is barely getting grip to thread. However it does not leak or anything like that, from lambda threads.
Hole drilled to pipe for lambda is also very small compared to thread size and I think that knob is bit too high too, leaving lambda kind of pocket.

But I would feel better when I do have proper oem solution, also lambda in exhaust manifold is less prone to exhaust leaks as there is one surface less to have a leak.

Also that garage did messy job with sealing exhaust manifold and downpipe, but so did other garage where I specially did ask to seal any leaks. I think that that could be reason why it would been running too rich if there has been too much oxygen in exhaust, but bit hard to say.

Leak was not very big, I did see that it was leaking towards engine when I did change downpipe to new one and I was suprised how much quieter was this new downpipe that has no lambda at all.

But when lamda did work I did adjust normal driving load area of fuel map so that I leaned it bit by bit until run was no smooth anymore and then came back a bit, so anyhow it should be quite near. Also there lambda did show properly that I was running near 14.7:1, until this 1st lambda decided that I'm running rich, I lean mixture and I'm still running same way rich as before, no matter what I did value reported was same.

Hard to trust to these after all these difficulties, so I came to conclusion that I must get oem solution for lambda, so that there is less variables to mess with.

[foggyjames]

Sounds like a plan

I still have no idea how you know what mixture you're running once you roll onto the throttle and you go below 14.7, as sure as hell the narrowband won't tell you!

cheers

James

[jtbo]

Sounds like a plan

I still have no idea how you know what mixture you're running once you roll onto the throttle and you go below 14.7, as sure as hell the narrowband won't tell you!

cheers

James

All I know is that mixture gauge does not go crazy and does not go to max, if I tune it to show 2 leds it shows two leds, if I make mixture richer by 2 more leds it will show 4 leds and if I lean it one led it will show 3 leds. Of course I adjust fuel map ot get end result of leds getting lit.

I don't care if it is not precise value, it just shows something near that and it is good with me.

However I should get new mixture gauge as I really can't see anything that goes leaner than 14.5, of course that is not truly accurate value either.

In Megatune I can see whole range from 0.000 to 1.000 Volts, but it is bit harder to read laptop that is on passenger seat than gauge that sits front of my nose

This morning (3pm) here was quite cold weather (-5C )and I had to do little cold start tuning to get car started. It started fine but died in second or two, that was because of warmup settings were not yet adjusted to this cold weather.
Lambda did work maybe bit longer, but it did give pretty insane values, there is no way it should be cabable of showing this...


Soon after it wen't back to 0 and stayed there even I did drove 20km.