I've acquired two 617.912 engines in the last couple of weeks; one in a 1981 300D California , and one from an unknown year, but non-EGR.

Neither have turbos, of course.

Both have ALDA controllers on the IP. I was under impression, from recent posts, that the ALDA is only used on turbo motors, and tunes the mixture under boost. Clearly, and ALDA is also used on N/A 300Ds.

What does it "tune" in non-turbo motors? Is it a mixture control strictly for emissions? Is there a way to set it with a CO/HC meter?

--frankb