512TR idle control motors. are they serviceable?

That is far more commonly the floor mat (I know it is never MY floor mat except it is the #1 cause of that by many magnitudes) or a mal-adjusted throttle cable. Also the throttle bell cranks need to be removed, taken apart and lubricated from time to time.
The cars are getting older but so far I have never seen a bad idle stepper motor. I have seen a loss of signal but not intermittent.

 

Agreed. Nothing much can go wrong with these things outside of the connector. All you’ll find inside are stationary magnets and a wound armature. There’s a worm drive and a spring.
They are essentially dumb actuators that just receive pulses that step the armature which turn rotation to linear motion through the worm. They do need an auto calibration on key-on especially in older systems. Similar to how older electronic speedos used to sweep back and forth.

 

I wouldn't think so. Unless it was badly overfilled with oil. Since 92 they have been so reliable I have sort of ignored them. I have had a few off to get them out of the way and never seen oil run out.

 

but I think this part has been from bosch?

 

A few companies beside Ferrari used Bosch parts.

 

From memory, they were supplied by Philips

 

I dont recall seeing a Phillips anything on a Ferrari except light bulbs.
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Honestly, when I read “idle air control valve”, I immediately thought it was this type which was primarily Phillips/VDO used on throttle bodies (later than what was used on the 512TR’s).
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