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[ady_botos]

Hi there,


I measured recently the emissions on my 33 (1.7 IE, CAt Conv, 1990, 140 000km)
and here are the results:

CO 0.32 %
O2 20 %
HC 120 ppm

In the book it's like this: CO < 0.2%
O2 ?????
HC < 70ppm


I know that my results are a little bigger than those from the book, but in reality what does it mean?

For a car with 140 000 km its a good result, or .....
Should I play with the CO screw?
I'm not shure, but does the value for HC (120 in my case) means that the car drinks more fuel? In fact the HC comes from unburned hydrocarbur, or am I wrong?

[Marcin]

Hmm, how can it be that you measure 20% oxygen in the exhaust gas? Even if you had a leaking exhaust pipe, it wouldn't reach that value.

Assuming that the other values are correct: from what I know, the CO level should not exceed 0.5% when idling and 0.3% at 2500rpm. The higher value could be caused by a number of things: engine too cold (thermostate, temp. sensor), worn lambda probe, cilinders fouled with unburned carbon.
High HC is often caused by oil in the combustion chamber, so worn piston rings or valve stem seals.

But to be honest, in your case I would say there is nothing to worry about. Maybe except the 20% of oxygen

Marcin

[ady_botos]

The engine was warmed up, above 80 degrees, and the HC value at first was higher (around 120) then after adjusting the idle rpm, the HC value started to reduce to about 80 or so. Regarding the O2 value (20%), maybe I'm wrong. It's more possible to be 2 %? What should be the correct value for O2, and if it's not, what is the cause?




tnx again

[Admin]

Hi

There is no adjustment screw on your car (as it will have a cat). The HC and CO are a little high. Try cleaning out the crankcase breather system, check the intake system for any air leaks.

All the best

Keith

[ady_botos]

My car has a Catalytic Converter, and as far as I know has a CO adjustment screw, on the right side of the AFM. (Jetronic).
Anyway, is it possible to "achive" a O2 of 20 % at the final exhaust pipe? Whats wrong?