Mixture screw

[uglymug]

Hi guys, have just replaced my plugs to NGKB7ECS and was going to alter mixture but cant find anything on which way it goes. Is it the one on the AFM or the throttle body, and anti-clockwise for making it richer...................cheers

[B@man]

AFM is the idle "mixture", TB is Idle speed

[Jack Valiant]

Only mess with mixture settings if you have access to a good quality gas analysizer, the Fuel - Air settings across the rev range are critical to good running on any of the EFi RV8's, lean it out at the top of the rev range and it could be very expensive!

Chris

[uglymug]

So , is it out to make rich or in to make rich ?

[honestjohntoo]

On your AFM

• This adjustment screw enables fine control of the actual airflow to alter the mixture strength and therefore CO content levels at idle speed.

• Turning the screw clockwise blocks the bypass port and so richens the mixture and turning it anticlockwise opens the passage to lean the mixture.

• The air in the bypass channel is not detected by the measuring flap so the ECU does not compensate for it by adjusting the fuel input.

• Just to clarify, it only affects CO content at idle speed.

• If you had a mind to affect the mixture over the whole range, that is far more complex and probably for experts only but if you are interested you can read how from here

Navigate to part 2 of 2. Whatever - be careful!

[adam quantrill]

Like wot HJ2 said - in case you missed it - the AFM screw only affects idle mixture. As soon as the flap/throttle opens up, the mixture is dominated by other things.

I've got a Gunson mixture meter and can set it up good enough with that, when it gets to the MOT tester it's within a few 0.1%'s of what I thought usually.

[maston]

Jack Valiant said:

Only mess with mixture settings if you have access to a good quality gas analysizer, the Fuel - Air settings across the rev range are critical to good running on any of the EFi RV8's, lean it out at the top of the rev range and it could be very expensive!

Chris

I'll second that