5 replies to this topic

[smj]

Hi, i know this problem has recently been covered but i am unsure of where to go with the answer, my 1994 rover mini sprite automatic has been for its mot today and everything was fine apart from the emissions, prior to the mot the car ran like silk, and was what i would call good on economy(never checked it mathematically but cheap to run), when the tester put the probe up the exhaust and started the emissions test the co and hydrocarbons went red on the machine, and so did the LAMBDA, he whipped the airfilter off, screwed out the mixture and dropped the co and hydro's far enough to pass, but LAMBDA didn't quite make it, and he failed the car, my question is, what is lambda, and why is my car checked on it when it doesn't have a sensor, in my downpipe there is a gas sniffer, but its open loop and goes nowhere other than up to the front of the block and has a screw in it, i assume fitted at factory as haynes explains clearly thats how it should be, the emissions results were co=0.046 and hydro carbons=26, clearly in his quest to lower lambda he has leaned the car right out, to the point in which it won't actually idle. and on the idle test the co =0.014.

My car does have a catylitic convertor, but has an HIF carb and is totally unmodified, there is no lambda sensor or ecu so emissions control is down to the carb and charcoal canister under the wing, has he tested my car wrong??? where can i find the information to present to him to correct him, i really don't want to fall out with him as the rest of the car flew through and he was helpful with the grease gun throughout!!!!

The garage that mot'd the car last year before i bought it were helpful on the phone, remembered the car and said there is an amendment in the emissions booklet for the mini, but i can't find it on the internet, and would like to have it with me when i go back on monday to see my tester, thanks for any help

[Dan]

There is a commonly held myth that there is a special note in the MOT manual regarding Minis. There isn't, why should there be? The Mini was required to comply with the same regulations as any other car at the time it was built. What there is however is the same set of rules that covers any other car in use between 1993 and 1995 that is fitted with a carb and open loop catalyst. All cars of this period that are presented for an MOT are put through the basic emission test, if they fail the tester is supposed to look up the car on his charts and see exactly what emissions levels apply to the car in question. This is what he has not done in your case. If the exact make and model of car in question cannot be found on the list then it is to be put through the older, 'non-cat' emissions test. None of the carb'd Minis of this period are listed so none of them have special emissions levels to comply with, they should all be tested at the earlier emissions levels. The levels for your car should be CO 3.5% and HC 1200ppm.

Your car has been tested incorrectly, how you choose to phrase this to your MOT tester is up to you but that is what he should have done. Remind him that it is an open loop catalyst, if the MOT computer has instructed him what test to run make sure the exact make and model of your car is correctly recorded on the MOT database for your registration. Furthermore if he has randomly played with the carb there is a real risk of damage to your cat and if it's that lean there is a risk of damage to the engine itself. The car now needs a tune up while the sniffer pipe of an emissions machine is connected to the sampling pipe you mentioned that is in the engine bay. This is the only way to tune it and be sure of keeping the cat safe.

There will soon be an FAQ about this.

Edited by Dan, 17 April 2009 - 04:42 PM.

[smj]

YOU ARE A STAR.

thank you very much for that info thats all i need, i know you had already told someone else but i read and reread it in a less than happy mood earlier with my pink piece of paper from vosa and couldn't figure out what to do, but after a cup of tea and a chill it now makes sense, thanks again

Mark

[m1n1]

MY 1994 open classic failed the test on emissions a few weeks ago. They performed a test for a injection mini not a carb mini (where the limits are much stricter) I went and complained a few days later and they realised their error and it then passed.

[MRA]

Dans spot on...... some MOT testers really don't know how to test a car all they can do is read a computer.... refer them to VOSA and ask them to phone up and check, also as Dan says you may need to make them (the company not the tester) aware that their actions could lead to serious engine or CAT damage it's of course up to you if you choose to take it any further.....

Most A or A+ series engines will need to be on raised engine revs due to the siamesed ports....... this is because cylinder no's 2 & 3 don't really do a lot at tick over. using the correct equipment remove lead no 2 and note the engine will not drop much in revs same for no 3

So the fuel going in to no's 2 & 3 are not being burnt that is why MG Metro's could be tested at 2000 rpm, however I have discussed this with an MOT tester (5 minutes ago) and what he is telling me is much the same.... elevated engine revs and it should pass, this is not a legal loop hole to pass any car that happens to fail at tick over......

[smj]

went back on monday armed with all your posts, mot man read through, thanked me for informing him, set my mixture so the co read 3.5, apologised for confusion on friday, and printed me a certificate, car runs really well, plugs are a rich tea biscuit colour after a 12 mile run to work, all seems well!! thanks for all your help. The mot man did say that my cat could come off the car, so i assume its fine to drop an rc40 on and drive on???