Technical Lambda probe in open loop

[Modano]

Hi Tipo enthusiasts.
The Tipo I've given to my mother has undergone the french MOT ("Contrôle Technique") and failed at the emissions tests.
French tests for such old cars (1994 - 1.6ie) are rather permissive, and it never failed for the past 5 or 6 exams.
The Tipo has 220 000 kms.

I have a Multi ECU Scan program and probed the ECU which indicates a permanent Open Loop on the lambda probe, stuck at 4.58 V, flat. Even after a 10 minutes run, still flat, no signal at all. I unplugged/replugged the wires, without success.

First, am I guessing right the ECU has no signal from the Lambda probe and goes in a alternate law that is emitting much more, only depending on throttle/temp/revs parameters , with a richer mixture ?

Then, how would you suggest (of course excluding trying a new one ) that it isn't the Connector to ECU wiring that is cut rather than a totally failed lambda probe ?

Then, other than this, what lever may I have to reduce emissions ? I was rather thinking that this ECU is all integrated with no setting whatsoever.
Also, I need to check the report, although I'm pretty sure it is a CO over emission, but can this be related to the catalytic converter ?

Thanks a lot

 

[SpaceBird]

The problem is your mother (lol) she is driving to slow...
My car had simular problems after a year of driving only short distances and low RPM's because of cold engine etc.
It has nothing to do with the ECU. A lambda probe is always possible but I think it is not the problem. (if you are not sure a new one costs you under 50 euro)
My mechanic had a simple solution. Take the Tipo out for an 10-15 minutes race while thinking you are Lewis Hamilton

In other words, heat it up and make some RPM's! 3500-5000
After done this my emissions value were ok and I passed the tests. Just "burn" it clean the engine!

 

[Modano]

Haha !
To be fairly honest, that wouldn't surprise me at all. When I had the car, I clearly pushed it, and revved it (including the fact I had 50 kms motorway per day) so I think it was not getting "dirty".

The only fact that bothers me is that this open loop issue did not exist last time I ran MES, 3 years ago, but I need to test back with revving up the engine while monitoring the lambda probe, as it may be open loop at idling, low RPM.


Thanks

 

[SpaceBird]

Haha !
To be fairly honest, that wouldn't surprise me at all. When I had the car, I clearly pushed it, and revved it (including the fact I had 50 kms motorway per day) so I think it was not getting "dirty".

The only fact that bothers me is that this open loop issue did not exist last time I ran MES, 3 years ago, but I need to test back with revving up the engine while monitoring the lambda probe, as it may be open loop at idling, low RPM.
Thanks

-
What is MES?
According to Bosch the lifetime of a probe is 160.000km. Check out the link below if you like measuring

.....A lot of downloads and how too's for you! ~Succes!
http://www.bosch-lambdasonde.de/en/downloads.htm
http://www.bosch-lambdasonde.de/en/downloads/pruefung_und_fehlersuche.pdf
http://www.bosch-lambdasonde.de/en/downloads/lambdasonden_systematisch_pruefen.pdf

 

[Modano]

Hi
MES stands for Multi ECU Scan, the tool to query the ECU , formely called "Fiat ECU Scan".
This one is able to check my loopness status of the Lambda probe I can see it osciallating from 0.2V to 0.8V if working

 

[SFB]

The last four cars I've owned with the Tipo have all needed at least one lambda sensor replacing, one of them needed both pre and after cat and the pre cat twice.
Neither myself or my wife are slow drivers!
Luckily, my Tipo doesn't have a computer with all the ancillary electronic garbage that causes at least 85% of breakdowns in these modern times.

Here's a link to some ways of testing lambda sensors:
https://www.google.es/webhp?sourcei...52&ion=1&espv=2&ie=UTF-8#q=lambda+sensor+test

 

[SpaceBird]

The last four cars I've owned with the Tipo have all needed at least one lambda sensor replacing, one of them needed both pre and after cat and the pre cat twice.
Neither myself or my wife are slow drivers!
Luckily, my Tipo doesn't have a computer with all the ancillary electronic garbage that causes at least 85% of breakdowns in these modern times.

Here's a link to some ways of testing lambda sensors:
https://www.google.es/webhp?sourcei...52&ion=1&espv=2&ie=UTF-8#q=lambda+sensor+test

-
According to my knowledge all Tipo's (SPI or TBI, the one injector type) have only one (1) lambda sensor.....
A pre and after lambda sensor I never heard off for a Tipo.....
Your (every injection) Tipo also have "a computer" called ECU (Electronic Control Unit). I am not talking about the carburator types now....
For older people like us who are afraid of "ancillary electronic" failures FIAT invented already long time ago the S.H.I.T. technology. (Self Healing Italian Technology) so don't worry too much! Cheers!

To have some fun check this out! - Thumbs up for Scotty!

 

[SFB]

-
According to my knowledge all Tipo's (SPI or TBI, the one injector type) have only one (1) lambda sensor.....
A pre and after lambda sensor I never heard off for a Tipo.....
Your (every injection) Tipo also have "a computer" called ECU (Electronic Control Unit). I am not talking about the carburator types now....
For older people like us who are afraid of "ancillary electronic" failures FIAT invented already long time ago the S.H.I.T. technology. (Self Healing Italian Technology) so don't worry too much! Cheers!

To have some fun check this out! https://www.youtube.com/watch?v=5icTmYItwiE - Thumbs up for Scotty!

I'm guessing that Tipos missed out on having more than one lambda sensor.
Mine has none, thankfully it has a carburettor.
Having spent the last few years of my working life in the motor trade, I grew into "ancillary electronic" failures quite easily.
It's obvious that the rest of the world adopted S.H.I.T., technology from Fiat.
I've not yet had a problem with catalytic converters, even though the ITV (MOT) inspector told me for the last two years that mine (Seat Ibiza) was possibly shot, he was wrong, of course.
What, me worry?
Have a good one.