How to set co on mk2 8v

[Slimmedmk2]

Hello,my 91 8v has just failed mot on co level being too high.Where do you adjust it??have never done before so dont know where to look
Cheers

[mk1]

There is a allen key adjustment screw in the air flow meter. Screw out to weaken the mixture, you need a gas analiser to set the mixture properly but you can guess by screwing out untill the idle starts to get rough, then in slowly untill a smooth idle is reached. When it goes back for mot, check the emissions, aim for 1.5% to 2% co.
Steve.

[richandhazel]

Not a lot to add to Steve's reply there other than, the allan key size you need is 3mm and it will need to be reasonably long.
You're looking for an approximately 5mm dia tube sticking up from you air flow meter......allan key goes in there. What ever you do, don't rev the car with the allan key in there......otherwise you will damage the metering unit.

When was the last time you changed the air filter? If its an old one thats quite clogged, that can cause your CO to rise........not too mention poor performance.

[Slimmedmk2]

cheers for the replies

[mk1]

Hey Rich, it's a '91 so should have digi. No need to remove allen key, can't remember the size, 6mm .
Steve.

[richandhazel]

Ah yes..........I was in k-jet mode, but you're right, it should be a digifant, in which case ignore my post other than the air filter bit

[Slimmedmk2]

Thanks again for the replies,the air filter is a k+n panel filter so is ok as is only a couple of months old.It was quite good,all the blokes from the garage were having a good look at the car saying how clean it is.