Etanol.nu

Hi Aryan, which spelling?
Is not easy for me to sort out sequence of letters. Hmmm, when I stare longer I can see German 'Arian'. I hope to remember this mnemonic aid next time
»Horst

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» Citroën BX14 E.CO.2 Break: TU3M/KDY (iron cast) C/R=10.3:1, AX-Diesel gear box (+22%)
» Citroën Ami8i Break: V06/630 + MS EFI + cat

Hello,
sad news. Was today in garage to ckeck emissions again (after checking valve clearence, spark advancce, hoses...)

~E74, driven ~60km, included 20km rather fast highway. ~1h lunch break, 4km warm up, air temperature ~15°, dry, sunny.

900rpm
CO 0.58%
CO2 13.5%
HC 124ppm
O2 0.9%
lambda 1.013
calculated: CO+CO2=14.08%

2040rpm
CO 0.72%
CO2 13.4%
HC 125ppm
O2 1.0%
lambda 1.015
calculated: CO+CO2=14.12%

I'm afraid I have to buy & weld a new universal catalytic converter.

»Horst

_________________
» Citroën BX14 E.CO.2 Break: TU3M/KDY (iron cast) C/R=10.3:1, AX-Diesel gear box (+22%)
» Citroën Ami8i Break: V06/630 + MS EFI + cat

Did you check whether the HC value dropped when disconnecting the crankcase ventilation? At least on Citroën/Peugeot with XU engines, this is an easy check of whether the high HC is caused by a bad catalytic converter or by a worn engine (piston rings, valve guides or valve seals). In some cases, the high HC value might also be caused by fuel that has congregated in the engine oil, in particular on cars that are used only for short drives in the winter. In the latter case, an oil change will fix the problem.

Also, i have had one case (that was an Audi 100 with KE3-Jetronic), where a bad lambda sensor caused a high HC reading but all the other exhaust parameters were ok. In that case, the sensor still had some functionality left but it reacted very slowly to changes in the lambda value, so the entire closed loop system worked too slowly.
This was easily identified by connecting an oscilloscope to the signal from the lambda sensor.

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Att mäta är att veta

Another cause could be a small exhasut leak in the exhaust manifold or one of the gaskets.

The lambda sensor "sees" too much oxigen then and the car is running too rich.

The best way to look for leaks this is too listnen with the end of a hose in one ear and use the other end to search for leaks.

Looking att your values I think you are right in suspecting tha cat.

Normal values are:
w cat wo cat
CO 0,05% till 0,5% 0,5% till 1,5%
HC 5 ppm till 30 ppm 50 ppm till 350 ppm
CO2 14,5% till 15,5% 13% till 15,5%
O2 0,1% till 2,0% 0% till 2,0%
LAMBDA 0,97 till 1,03 0,9 till 1,1
AFR 14,4/15,0 till 1 14,5/16,0 till 1

/Aryan

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Komplettera gärna data om dit piggybacksystem här: http://www.editgrid.com/user/aryan/E85_piggyback_system och här viewtopic.php?f=10&t=6352

Hello,
I'd like to give you a report about 'solution' of emissions troubles.

torbjorn,
yes I removed the oil seperator, cleaned all and added also another one to improve seperation. No sucess.

I also changed the O2 sensor and tested some. I recorded 2 of them with MegaSquirt controller:



I think the cross overs are fast enough.



Aryan,
yes you're right there was a small leak in the gasket a couple of cm in front of the O2 sensor. Unfortunality I detected this recently, but I can't imagine that fresh air is sucked in - I think this leak causes pollutes air with a smaller O2 partial pressure --> sensor detects 'lean' mixture.
Now this is fixed. Also the lost screw down under the engine/gear box is replaced to keep the pipe in correct position.

Thanks for the hint to find this. I felt the blowing exhaust after cold start, later its was too hot there.

Thanks also for the emissions ranges.




Continuing the story: In 2008 I bought a new aftermarket universal catalytic converter (Uni Fit) which are all the same but with different diameters to weld them onto the OEM exhaust pipe. They're designed for engines up to 2.5l and far over 100hp --> No problem for my weak 75hp engine.

2008 I passed hardly the emission test. I don't know which fuel was used.


June 2009: I had to pass the test again, but failed. What to do? (~85% Ethanol inside)

» The ex Pug mechanic told me that Equiem spark plugs are necessary. I don't believed him what when you've no idea you try esoteric tuninng.

» I checked the vacuum hoses again. When I used a brake cleaning spray I could detect a worn out hose (connection to the top of the air box (oil seperator)). When I reparired this, idle decreased (which was rather high sometimes before).

» Showered the MAT sensor a few times, maybe the oil film changes resistance characteristics. Was also a hint, no costs --> whay not.


I couldn't believe but test failed again!

» I had the chance to replace the O2 sensor (had one in car). The mechanic told me to warm up the sensor driving around a little bit.

» I filled up Eurosuper so that Ethanol is lowered from 75...85% down to 40-50%.

» Then I rode the car rather hard for about 4 kimomteres.

When I reached the garage I could do the test at once:
at idle (numberes written from the exam, maybe born by phantasy:
CO 0,01%
HC 18ppm
2200-2500rpm (asked for print):
CO 0,04%
CO2 14,7%
HC 18ppm
O2....0,2%
CO-VRAI 0,0%
Lambda 0,993

Oh god, what a damed job!
What's the reason that the test was sucessful finally?

I think that E85 exhaust is too cold to get the aftermarket cat work properly (under test condtions = no load = just few gas flow).
Yes Aryan, I remember that you told me that you have to run the engine at increased idle to pass the test. It's not wanted in Austria to heat up the cat in such way.


I'll add a K type thermo element in front of and after the catalytic converter to find out more about its working conditions.


Thanks uys for your help, I'm not sure if I will try the next time with E85 inside...

»Horst

_________________
» Citroën BX14 E.CO.2 Break: TU3M/KDY (iron cast) C/R=10.3:1, AX-Diesel gear box (+22%)
» Citroën Ami8i Break: V06/630 + MS EFI + cat

Yes this is what I meant although I would not be surprised if some air enters the exhaust pipe too, either way, the sensor sees a mixture that is leaner than it really is and you will end upp with a too rich mixture.



Have you checked that the lambda signal that the ecu gets is "normal" when you do not pass the tests? If it is too high or too low you obviously cannot get good emissions values. I'd start with using the built in error reporting system and chck for what faults it reports. If your ECO gos ino a limp home state on E85 the idle mxture gets to rich and you will have a hard time passing the test, even though the emission values normally get lower if the system works as intended.

Att the Swedisch MOT they you need to pass the test on idle and @3500 rpm, but if the emissions are to high, they take the car on a tour and drive it on a (too) low gear to get the engine warm and ignite the cat.

An EGT termocouple near the cat and compaire fuels would be an interresting test, i have been considering to use ThermoTec exhaust insulation wrap to get the catalist warmer quicker but haven't done any tests.

ggreetings, Aryan

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Komplettera gärna data om dit piggybacksystem här: http://www.editgrid.com/user/aryan/E85_piggyback_system och här viewtopic.php?f=10&t=6352

Hello Aryan,
I can't remember 100.00% correctly but I think lambda was ~1.0. Otherwiese it would be easy to recognize that something is wrong.
Also I use (most of the time) another quartz (5.2MHz?) so that mixture is enriched automatically --> ECU does not swap to limb home mode.

In Austrias MOT emission test the increesed idle has to be higher than 2000rpm. ECU and cat has ~30s time to reach the correct limits. If the engine is warmed up, the catalalytic converter has to be active even after some minutes of parking.

Yes, an insulated exhaust pipe would be good for emissions and less heat under bonet. One time I read that this is done to tune the engine (other oscillating waves in the tube?).

»Horst

EDIT: Today I had to pass emissions with Visa engine (removed cataylitc converter). I had no time to fix. There is any tach bug so that read rpm jumps sometimes up to 2000rpm --> silly mixture, no closed loop.
It was enough to pass but I was not satisfied:
~700rpm
CO 0.951%
CO2 9.3%
HC 253ppm
O2....6.8%
CO-VRAI 1.4%
Lambda 1.388

_________________
» Citroën BX14 E.CO.2 Break: TU3M/KDY (iron cast) C/R=10.3:1, AX-Diesel gear box (+22%)
» Citroën Ami8i Break: V06/630 + MS EFI + cat