I hope this isn’t too n00b of a question around here, but searching on here and Google didn’t turn up anything for me.

My my car is dropping about 200 rpm during idle whenever the AC compressor kicks on. The idle is currently a bit high so it’s not a big problem, but it might become one if I end up adjusting it down to an idle rpm of around ~800 rpms.

Upon further inspection, it looks like the A/C bleed air valve (part number 928-606-215-01) is missing along with all of the associated tubing and wiring that would connect to it. I suspect that this might be what’s causing the idle rpms to not be compensated when the compressor turns on.

Is there a mod out there that would entail removing these components? Im still a bit new around here so there might be a common modification that has this removed. Also, am I on the right track in thinking that having this valve missing will negatively affect idle rpms with the air conditioning on?

The car is a 78 with the 5 speed.

Thanks folks.

Mine is a Jan. 78 build. #0338. That would explain it!

So if that’s the case, then do these early OBs simply require a higher warm idle to compensate for the AC compressor compared to later 928s?