tried setting the mixtures on my s1 (mfi) but the adjustment screw is not the proper one..it has a small bolt instead of the allen type (i think thats correct?)..the car runs but is quite lean..co level only 1.6% instead of 3% so ive been told..what im wanting to know is can i put a longer bolt in it as i think the screw needs turning more clockwise to increase co level..also what other things have you done to replace seized mixture screws..cant seem to get hold of a good second hand 1 with allen screw intact and not seized..thanks

 

It might be that the bolt is simply the bung to prevent an air leak, and if you take it out the allen key adjuster is underneath, thats whats normally done. Otherwise If what you say is accurate then the metering unit will need stripping down to remove it if it is seized!!

 

i'd echo wot karlos has said and say it some sort of sealing screw- hopefully the adjuster screw underneath isn't damaged.

 

thanks for that...when i removed the bolt the car cut out so does sound like a bung like yous said..i was getting a bit of difference in co level but not very much..do u know what direction the allen screw needs to be turned to increase co level..thanks again

 

Cutting out is a good thing, means your breathers are not blocked
Clockwise is rich, anti is lean, 1/4 of a turn will make a difference to how it idles so should notice as you are doing it!

 

basic set up, take off the filter, when its idling, push the paddle down 2mm, if it dies a bit, its rich, if it goes up,its lean

 

thanks..how will i adjust the mixture tho when the screw is out as it cuts out?

 

lol! You hold it on the throttle body so it doesnt stall, once you have inserted the allen key it should not stall anyway, if it does then you are very lean! Just turn 1/4 clockwise and fire it up again.

 

Make adjustment and use your finger to seal the opening while taking a reading.
Remember that the original CO figure from Ford was 0.25%. To set it really rich is usually done just to compensate the fuelling for higher than standard boost.

 

No it isnt! It only adjusts the idle mixture, nothing to do with on boost fuelling at all.

 

lol never thought of that! thanks pal..probably pushing my luck here but what size id the allen screw cos mine looks like it tiny but has a bit of crap on it so cant see properly..its currently at 2% max CO at the minute..im aiming for 3.5%..is this correct roughly cos theres a few mixed comments on here and you seem to know what your talking about ha

 

3mm allen key

 

Yup!


I never set mine using a CO meter, just set it so it idled nicely!