Idle Speed and Air Temp/Humidity Options

[StarBear]

As getting ready for the 2022 Northeast Gathering, I'm encountering a semi-recurring idle issue on my 1974 1.8L LJet FI. When outside air is cool and dry, idles just fine at 950-1000 rpm. When outside air is warm and humid, after warmup the idle falls off to barely running. I've just been adjusting the air flow screw (maybe 1.5-2 full turns) to open it. Of course, the reverse happens - if I preadjust the screw it idles near 1800 then settles down to 1100 after the engine gets totally warm (15 mins or so).
I presume (?) there SHOULD be some regulation, perhaps with the ECU or AFM, to monitor air temp and humidity and make adjustments automatically? I didn't have to manually do this adjustment in the past.
The AAR works and tests out fine. Just annoying to have to pull over after running a while and adjust the screw. (IMG:style_emoticons/default/dry.gif)
Your thoughts @Van @Van_B and @Wonkipop ?

[Van B]

The Porsche manual does a terrible job of breaking out year to year changes. I know the 75 has a 7-pin and the 74 a 6-pin. And the manual only says to test resistance between two sets of pins for a pass fail.
Either way, I still think there's no issue with your car other than seasonal allergies!

[StarBear]

The Porsche manual does a terrible job of breaking out year to year changes. I know the 75 has a 7-pin and the 74 a 6-pin. And the manual only says to test resistance between two sets of pins for a pass fail.
Either way, I still think there's no issue with your car other than seasonal allergies!

Hehehehe. To my best (?) reading, the D-Jet and 912E LJet have an air intake temp sensor but the 1.8 doesn't as it only has 6 pins - until maybe later with the 7-pin.
@wonkipop I checked Mr. B's website and can't find your reference; there are a few LJet manuals but none seem specific to the 1.8. My guess is that the 1.8 has Temp Sensor II (CHT sensor) but not the intake one?
Meanwhile, will try to figure out testing the butterfly as Van suggested.
Have cleaned the AFM and ECU contacts with electrical cleaner spray followed by air blast.