10 replies to this topic

[rajah]

1984 Mini 25
Just failed MOT and one of the reasons was CO level of 4.18 against a criteria of <=3.5%, yet looking back on my previous two test results the previous criteria was 4.5%
Has there been a change in the CO emission level permitted since this time last year?

I've searched around the net for anything official from VOSA but can't seem to find anything. Does anybody have a link to the up to date requirements so I can have a friendly chat with my MOT centre.

[newdawn1st]

Have a look here Click me

[rajah]

Interesting, but I'd love to see the relevant page from the current manual relating to a 1984 Passenger Car

[1984mini25]

Nope the max co limit for an 84 (I should know as I also have a 25 and have the same problem come mot time) is 4.5%

The 3.5% it's been tested against is for cars registered late 80's to about 94.

Although just so you know it should be tuned to about 3.5%, so would if properly tuned just scrape through the later test.

Edited by 1984mini25, 05 June 2009 - 09:39 PM.

[newdawn1st]

Yep just found this Linky

scroll down to 22

At the time of writing, for vehicles first used between 1st August 1975 and 31st July 1986 (P to C registration), the CO level must not exceed 4.5% by volume. For vehicles first used between 1st August 1986 and 31st July 1992 (D to J registration), the CO level must not exceed 3.5% by volume. Vehicles first used after 1st August 1992 (K registration) must conform to the manufacturer's specification. The MOT tester has access to a DOT database or emissions handbook, which lists the CO and HC limits for each make and model of vehicle. The CO level is measured with the engine at idle speed, and at "fast idle". The following limits are given as a general guide: At idle speed - CO level no more than 0.5% At "fast idle" (2500 to 3000 rpm) - CO level no more than 0.3% (minimum oil temperature 60ºC) If the CO level cannot be reduced far enough to pass the test (and the fuel and ignition systems are otherwise in good condition) then the carburettor is badly worn, or there is some problem in the fuel injection system or catalytic converter (as applicable).

[rajah]

That squares with what I'd been finding out - looks like having a polite little chat with the MOT centre in the morning.

Previous years readings were 2.74% and 3.26%, so could definitely do with some adjusting to improve from where it is now.

Many thanks.

[1984mini25]

Yep just found this Linky

scroll down to 22

At the time of writing, for vehicles first used between 1st August 1975 and 31st July 1986 (P to C registration), the CO level must not exceed 4.5% by volume. For vehicles first used between 1st August 1986 and 31st July 1992 (D to J registration), the CO level must not exceed 3.5% by volume. Vehicles first used after 1st August 1992 (K registration) must conform to the manufacturer's specification. The MOT tester has access to a DOT database or emissions handbook, which lists the CO and HC limits for each make and model of vehicle. The CO level is measured with the engine at idle speed, and at "fast idle". The following limits are given as a general guide: At idle speed - CO level no more than 0.5% At "fast idle" (2500 to 3000 rpm) - CO level no more than 0.3% (minimum oil temperature 60ºC) If the CO level cannot be reduced far enough to pass the test (and the fuel and ignition systems are otherwise in good condition) then the carburettor is badly worn, or there is some problem in the fuel injection system or catalytic converter (as applicable).

That’s the bit I was looking for… new it was about somewhere as the last place I had mine tested tried putting it through a cat test meant for cars from late 94 onwards.

[rajah]

Brilliant link to Haynes on line which gives me the definitive answer to 'chat' to the MOT centre with, if needed!

[newdawn1st]

Happy to help, might even push for the mods to pin this, seems to come up a bit

[rajah]

After a very pleasant little chat with the MOT centre this morning, they confirmed they'd put the wrong setting in the analyser and the criteria should indeed have been 4.5%, so the old lad's passed his emission test.

Just a sticking brake and a bit of welding on the rear offside heel board to make him legal again (and that's all being sorted next week).

Next thing might just be a new carb though (or at least a reconned one) as there are a few problems that would probably be sorted out by that.

Again, thanks for the help and advice.

[newdawn1st]

Glad you got that bit sorted, see what a nice calm chat can achieve, especially when you can back it up