Setting Exhaust Emisions For Mot?

[Guest silver 1600]

My 1.6 GTI failed its MOT yesterday just on the CO level being to high. As you can see by other post i have serviced the car today and what i was wondering is there anyway of adjusting the exhaust emisions without a gas analiser as i no longer have any access to one these days . Or is there anyway of getting the the CO level low enough to pass the the MOT

Any input would greatfully receved Cheers again Neil

[Ahl 4]

What is it idling at? I think you can increase the idle, then it'll put out less CO.

 

The other thing you could do would be to adjust the air bypass on the Air Flow Meter. This is a hex bolt that goes down into the AFM.

 

Take it out, give it a clean and also spray some cleaner down the hole. Then put it back in, but only screw it in enough so that the car idles ok and no more.

The further the bolt is in, the richer the car will run at idle, and hence the more CO that will be produced!

 

 

The other things you could do would be to take the car for a good long blast before taking it for the MOT. Also make sure all the ignition compenents are in good nick - you want as complete combustion as you can get. Also clean out all the induction pipes, including the inside of the AFM (around the flap etc).

[Guest silver 1600]

Ok thanks for the Info i will give that a try

[Higgy 0]

silver 1600 - I would have thought a garage with any sence would have just adjusted the idle mixture screw so your car passed? I knew mine was out and took along a screwdriver ready to adjust it. For the MOT computer it was put down as FAIL, but 'fixed on site' (to helps to show that the garage is failing cars to keep VOSA/DVLA happy ).

 

I would say it's very difficult to detect the CO levels without an 'electronic nose'. You could always get the engine warm and drive down to a garage and offer a tenner and say can you just check my CO levels, and take an allen key + screwdriver with you to adjust the CO and/or idle speed.

 

Good luck,

 

Higgy.

[Guest silver 1600]

Right i have taken out both mixture and idle screws and cleaned them up and the ports in which they screw in to. Then i have rewarmed the engine and adjusted the tickover and mixture to ear and nose as good as i can

something i used to do back in my Mini days

Now I have called the MOT station and arranged to take the car over in my lunch time on monday and recheck the emissions and adjust them if needed so hopefully fingers crossed I will have an MOT on monday

Cheers everyone for the pointers

 

Neil

Edited December 16, 2006 by silver 1600

[Ahl 4]

Good luck fella!

I've adjusted that lot a few times to pass various cars. Seems to work well too, bring the CO level from maybe double the allowed amount to practically nothing!

 

How much above the limit was your CO level?

[Guest silver 1600]

The CO level was at 4.44 percent so it was a little high

But the exhaust fumes smell quite a lot better now

[Miles 331 1 Cars]

turn the tickover up, easy fix and even alloed in the rule book on older cars

[Simes 248 2 Cars]

As Miles says you can run the test at higher rpm.

Mine fails at 1000rpm but waltzes through at 2000rpm.