I wouldn’t take those pics of the ‘74 as certain @wonkipop . Not the same as mine and both mine are identical.

yeah i noticed looking at the one you posted up you can see two wires there that are black coloured and fit snug down. maybe yours is a rebuild?
also the counterweight!!!!!

i could crack mine open and we would know.
its original from the factory.
but i'm not going to.

what i will do is undo my aircleaner etc and peer in there at the intake.
the temp sensor should be visible hanging down.
no spare time at the moment and not urgent.

main thing - we know its there (somewhere/somehow) and there is farken well narthing you can with one if its cactus!

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i did poke around in 912 universe,
sure enough you can test for temp sensor I
must have been able to do same test for the 75 914s?
just not in the copy of factory manual we have.



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@StarBear .

just noticed something about your T/B looking carefully at the photo at top of page.

the throttle body gasket looks a bit wonky.
you can seen how its got a ripple in it where the little formed ledge looks to have moved away from the T/B edge.
maybe its not sealing well?

i had a problem with a gasket that had gone hard a couple of years ago and it sent the idle mental.'
worse than what you have been describing.

maybe make sure its still seating in nice.

Yes; will do cold and hot test on pins today. Might have a photo of my AFM internals from when I had it open a few years ago.
The TB gasket should be fine; finally replaced it about 2 years ago but will recheck and tighten to be sure.
In the home stretch!

Update 2:
+ did the pin tests in cool garage with 6-9 at 324 ohms and 7-8 at 164 ohms, both within spec. Will check again after a drive and warm day air and engine.
+ @wonkipop Good spot on the TB gasket! Maybe some fine hair gaps on the edges. Temp fix with fill in with black RTV. Will let set then do another test drive. If needed, I have a spare new TB gasket.

Second test run for 20 min done.
Pins 6-9 at 324 ohms before starting. At end ohms varied widely, 961 to 1005 to 324 to 201 about 20 secs apart. Sometimes no reading at all, even after relearning pins.
Pins 8-9 very steady at 154 and 164 ohms, as before, about 20 secs apart.
Idle Behaving better but still not to my satisfaction. Looking at replacing the TB gasket.

Apologies to the group for posting photos of what I believed to be the AFM from a 74. @Van B alerted me to the possibility that the photos were incorrect. I believed it to be a genuine 74 AFM as that was the AFM that came on the car when I got it.
I popped the top of the AFM which is on the car and indeed it is quite different inside. I don't know where the other AFM came from as the black plastic cap bearing the part number has been lost. Updated photos below. There are 2 black wires coming from the position of temp sensor ‘1’
I looked up PET and the change over point for the different AFM and ECU is the same – engine # ECO 037 551. 6 to 7 pin change over. No surprises there

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Yeah that is definitely the ‘74 AFM right there!

yes
more like what i thought it would be.

i would say that counterweights on the units that @nihil44 has posted in the other thread are due to them being rebuilt units? the counterweights don't appear to be stock? the unit above looks stock.

it seems to me on the 74 that the temp sensor is feeding into pins 9 and 8 on the plug socket - as much as i can tell anyway and its modification of the signal is fed out via that circuit to the ECU.

the later ones in 75 are using pin 6 and an additional pin 27 added to the plug and ECU.

would suggest you might be able to test 74 AFM by taking the top off and testing at those two electrical connections from temp sensor I? if you had test reading data to check against? dunno. only ever found that 912 test.

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not sure what to make of @StarBear test above.
seems like his AFM is correct when tested cold.

can't really think what to make of his warm test or the why of it.
the AFM is sheltered from engine heat. isolated via intake boot and plastic air cleaner casing from direct engine heat conduction and is perched high in engine bay. i guess electrical circuits are all warmed up. but don't know what to make of it. don't think it matters. his test would seem to say his AFM is ok.