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 ?

[wonkipop]

i'm just curious about it @Van B .

its not the problem with Steve's car.
i've read up on what happens if the temp sensor is kaput.
and the symptoms are a lot worse than a high idle. (IMG:style_emoticons/default/beer.gif)

i wouldn't even mess with an AFM.
there is a bloke here you send them to who fixes them and knows what he is doing.
i'm tempted to contact him and ask him about the AFM on our cars and see if he knows anything about this and whether and how there is a way to service this sensor on our cars if its not easily removable. i'm betting there is.

the bit of history i have read about these things when they first came into being was that they were classified as part of the emissions system and by regulation had to be tamper proof. if there was a problem with one VW removed them from the car and just replaced the unit completely. they didn't throw them away, they were sent back to the bosch factory in germany and i'm guessing, rebuilt there. using factory facilities and manufacture techniques. so a built in temp sensor would have been a little easier for the factory itself to deal with and replace if it was faulty.

i think as the technology was taken up and the numbers got big they decentralised servicing and repair of these items and made them easier to dismantle and replace defective parts inside them.

effectively our cars and 412s are numero uno with this tech. so we probably have the version that no one is supposed to touch except the bosch factory back in germany.
hence a version that was never intended to be looked at except by factory techs.