Air intake sensor adjustment ?
 

There is an adjusting screw on the L-jetronic air intake sensor. I did mess a bit with it but it doesn't seem to do a big difference. The Haynes manual indicate that it it used to adjust the exaust gas CO content. How do you do that ? Does it affect the " performance " of the engine ?

It is a bypass around the air door for idle mixture adjustment. It only affects the mixture at idle and does not affect off idle performance.

Thanks James That makes sense.