Hi, all.

The AMM on my '84 (240DL, normally aspirated B23F) just died a classic death (wouldn't idle; disconnected the AMM, and then it would idle). So I ordered a replacement from FCP (who deserves much credit for having terrific prices) -- a new Bosch unit (not a rebuilt) -- original and replacement p/n's match.

But this new unit has something interesting. As you look down at it, leaning over the left fender, in it's properly mounted position, there is what appears to be an adjustment screw just to the upper left of the 6-pole electrical connector.

On my original unit, it was apparently covered by a cap (with two holes) -- this lacks the cap, exposing the adjustment screw and piquing my curiousity.

What's it for? And more important, concerned as I am about passing future emissions inspection, is this something that could, by adjusting it, help me pass future inspections (my state does the dreaded dynamometer or treadmill (i.e., roadspeed) emission testing.

Thanks all.