Emission values

[mauro12]

Hello guys , I’ve recently overhauled my injection pump and today I did the emission test ( in Italy is mandatory a check up for every vehicles every 2 years ). The emission test have been passed but I believe the idle test in the picture shows a bit too high CO . Probably I need to re set the inj pump screw at idle and correct the mixture but the car is running great so far and I’m scared to touch anything . What do you suggest ?
Thank you

[dirkbalter]

if it ain't broke, don't fix it.
 

[mauro12]

thank you , i was only wondering how these emissions are . Im sure i need to bring the co down a bit but maybe the car is happier with more fuel. Any assessment is appreciated.

[rwmastel]

Seems that getting CO low enough to pass a test is difficult.  I did a search for emission test and found a few pertinent entries among many random things.

https://www.sl113.org/forums/index.php?topic=13361
https://www.sl113.org/forums/index.php?topic=14851
https://www.sl113.org/forums/index.php?topic=30005
https://www.sl113.org/forums/index.php?topic=15631
https://www.sl113.org/forums/index.php?topic=2087

And, if you feel like reading more material, there is this: https://www.sl113.org/wiki/Electrical/EmissionControlSystem  Perhaps you'll find a problem with your system that will help you reach lower CO levels once fixed?

[dirkbalter]

thank you , i was only wondering how these emissions are . Im sure i need to bring the co down a bit but maybe the car is happier with more fuel. Any assessment is appreciated.

Mauro,
take a look here.
https://www.youtube.com/watch?v=28uD3JVbQ-I

May be that helps

[Cees Klumper]

I have a Gunson CO tester and that allows me to tune the CO down to below 5% where (if I recall correctly) it was required to be when the car was still in the Netherlands.
Mind you, I set it only at idle, with that air/fuel mixture through the large screw at the back of the FI pump. The engine runs very well at that <5% level at idle. At normal speeds, I really don't know what the CO values are, but my car always gets through the semi-annual testing now here in France. 

[dirkbalter]

I think the theoretical CO2 level published by MB for these cars is 4.56.
From what I have red, some guys feel that the cars run better with a slightly higher CO2 level.
What are the your guys at the inspection testing it to, if not to the specifications?   

[mauro12]

The emission test was passed anyway. The limit was 9.99. How about the HC value ?

[stickandrudderman]

It should run fine at 4.5%. If the car won't idle smoothly at 4.5% then certainly you can richen it up to 6.5%  to try and improve things but 9% is way too high. You'll be fouling your plugs up in no time. Be careful that it's not stuck on cold start though; that will give high Co.
Your HCs are also a little higher than ideal but an "Italian tune-up" will probably resolve that.

[mauro12]

The cold start has been overhauled and is not leaking . Probably I need to set the idle screw ccw and add more air with the idle screw.
The pump has been completely overhauled and the car is running great . Plugs are not fouling . They look between black and brown , more black .

[rwmastel]

This thread sheds some light on original emissions measurements.  Just double check those units of measure!
https://www.sl113.org/forums/index.php?topic=37175.0

[mauro12]

Well , you have to make some conversion in order to have the result . This is gram per mile . We are measuring at idle so I’m not so sure ..

[dirkbalter]

Mauro,
found this for the 130 motor, the 129 should be similar.

[stickandrudderman]

That extract from the technical data book is out of context.
Not all M130 engines are the same.

[dirkbalter]

That extract from the technical data book is out of context.
Not all M130 engines are the same.

That’s why I said similar. He is also talking about a 129 motor with a picture of what looks like 9.5% CO2. I think with above levels you are definitely within ball park. If you  have  better or more precise data, by all means ….