There is an "adjustment" screw on the backside of the AFM (rear not the underside) what is this for? It appears to have a tunnel running back to the "sensor area on the "front" side.....what is it ?

 

No body kn0ws?????? it's an s4 btw....come on fellas help a poor white boy out.

 

It's a calibration adjustment for bypass on the AFM flapper door.
I do not recommend you mess with it, as it'll mess up your idle.
This has nothing to do with performance, so there's no reason to mess with it in the first place.


-Ted

 

Yep, Ted is right... it is a calibration adjustment.

Think of it as a $400 ****... you turn it and you buy a new AFM because your current one will no longer work correctly.

 

well i was looking at it and noticed that it is in a completely different position on my 87 then it is on the 86...the 86 is stock and the 87 has had a rebuild and is streetported....the 87 has a wierd idle sometimes and the air fuel ratio is out of whack...could the adjustment on this one be the problem? If so i'll probably swap out afm's...

 

Like they said it's a calibration **** so it might not be the same on eah AFM.

 

The units are calibrated from the factory.
It's fine that the screws don't match.
Don't blame the screw for bad idle unless you know for sure it's been tampered with - look elsewhere, as there are a lot of other things that can screw your idle up.

intake vacuum leak
bad spark plugs
bad spark plug wires
bad coils
dirty fuel injectors
idle mixture screw out of adjustment (for Zenki only)
fuel filter dirty
fuel pump bad
FPR bad
air bleed valve cracked
bad wiring
And that's just a SHORT list...


-Ted

 

Yea ted is right you dont wanna **** with that, it will be one expensive adjustment...!