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]

That’s a differ AFM than both of mine.
The one I tuned on was a NOS Bosch reman that was meant for a bus, so it was tuned way too lean for the 914… I guess the Porsche heads do make a difference.

The other is the part that came on my car with a FI Corp rebuild sticker on it. I haven’t messed with that one.

Regardless, both have the same guts and neither look like that.

I’ll have another look though.

[wonkipop]

That’s a differ AFM than both of mine.
The one I tuned on was a NOS Bosch reman that was meant for a bus, so it was tuned way too lean for the 914… I guess the Porsche heads do make a difference.

The other is the part that came on my car with a FI Corp rebuild sticker on it. I haven’t messed with that one.

Regardless, both have the same guts and neither look like that.

I’ll have another look though.

yeah its going to look different to these.
these are 10 years later i think.
but pretty sure thats the temp sensor with the two phillips head screws and the two wires coming out in these later ones - and it looks like that so that it can be serviced and replaced.

in photo of yours it looks like there is something with two wires coming out of it and heading towards the interior side of the pin plug section in the same location. the wires look a lot flatter and "integrated" in yours. as if its more "built in" it will be in that spot if its there, it just won't have the ability to be removed.

i'm going to take the BMW photos and your photo to mike when i see him next.
he is going to know for sure.