CO emissions readings on 350i

[dukeenfield]

Hi,Does any body know what the CO emissions is on a 350i at idle,in the Rover haynes manual it says about 1.5 to 2.5%.Also would the emissions be the same or there abouts when reving engine (say about 3000rpm).
I have just bought Gunston emissions tester and I am trying to get an idea if engine is a bit weak at higher rev range.I have looked at spark plugs and they are a very light guey colour,but not sure if it's a bit weak.
When I had MOT test the tester said it was a bit weak,about 0.80 co.thanks Ken.

[19560]

dukeenfield said:

Hi,Does any body know what the CO emissions is on a 350i at idle,in the Rover haynes manual it says about 1.5 to 2.5%. When I had MOT test the tester said it was a bit weak,about 0.80 co.thanks Ken.

All sounds OK. Just had my MoT today. Emission was 3% not properly warmed up. (Limit is 3.5%)

[dukeenfield]

Thanks,perhaps no body knows anything about emissions figures.

[Gerry Attrick]

I've been through the emissions measuring loop a few times when trying to set up the AFM following an earlier botched attempt. On mine the idle is about 2.5%, but it will seem sweet down to about 0.5%. The problem below about 2% is that the pick up becomes too weak and you can get a misfire at light throttle - makes town driving difficult. Coming down the rev range when slowing up, anything less than 1% at 2000 rpm gives shunting. I've found this is the most difficult area to get right as there are a number of components to juggle. Firstly the tension of the AFM flapper (which shouldn't need adjustment as I understand it doesn't wear), secondly the spring pressure of the over-run valve (which does wear), thirdly the idle by-pass and finally the mixture screw.

My advice, unless you want to spend hours at it, would be to set the idle at between 2% and 3.5% (MOT limit) and leave it at that if it runs without problem.