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[anders]

My 33 16v 1990 failed the emissiontest.
All the emissionvalues is fine at idle,but when tested at 2500 rpm
the CO emission are 3.5% (maximum allowed 0.3 i think).
Also the Lambda value is too low 0,87.
I have changed the afm,oxygensensor,catalyst,ecu.
Oil and filters sparks also.Checked compression and it was fine.
Please if anybody have any ideas how to solv this problem I would be very happy.
Best regards.
Anders.
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alfa 33 16v

[Admin]

Hi

Not sure about the emmisions test you have to go through.

However I would be tempted to check that there is no air leak into the exhaust manifold, that the crankcase breather is clear and that the throttle position switch is correctly adjusted.The first 2 of these can cause odd emmisions problems, while the 3rd might well be worth a try depending on how much throttle is required to attain 2500rpm.

All the best

Keith

[BILL]

Hi,
did the engine temp was ok when checked the emmisions ?
It should be around 80 to 90 C for the cat to be heated enough and to work properly.
Also try to fill the fuel tank with premium fuel (better quality ,cleaner fuel),it gives better cleaner emmisions(at least thats what the advertise says).
I am going for a technikal exam myself(my 33 actually)in a week so im cheaking everything in the car .I ve checked the emmisions one month ago at a repear shop and it was fine exept the O2 sensor wich over 2500rpm wasent doing a good job so i changed it .
Then the ecu connected to a computer they had(sort of a handheld computer)to reset the memory of the fault that the O2 sens gives back to the ecu, they
said its very important to do so or the new O2 did not work ok.
Also check that all the butterflys(you have 4 right?)have the same opening point and same angle .

[gritsop]

Hi,

I also had problems with the emmissions test which was attributed to the normal running temperature.

The car was at about 100 C when the test was done BUT it was only 10 minutes that the car was running. Of cource the HC and CO2 levels could not be stable.

After that I went to the original AR garage where I used to go some years ago and the test was successful. What the mechanic told was that not only the engine should be at normal running temp. but the exchust system must be also warm enough ; this means something like "city" style driving 1st - 2nd gear stop at traffic jams ... etc. This will result in a complete running temp. which comes after 20 approx. minutes.

In addition the supplement manual (can be found at sanderfamily) clearly indicates that conversion does not occur at all at low temps.

Try to do a small trip around your area , operate the car for 20 minutes , go to traffic jam for a while and only after that do the emisson test; probably you may have correct results.

We ll wait for your news

Regards,
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
Parts Shop: www.alfa-restoration.co.uk/shop

[anders]

Thank you all for your advice!
I will have a look at my car this weekend and I hope to find the problem.
Have a nice weekend!
Best regards
Anders
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alfa 33 16v