I took it apart again (getting really good at it now) and verified that the IAC valve is indeed oriented in the correct position. The arrow points into the manifold.



I started it up and it idled rock solid, starting about 1,000 rpm when cold and decreasing to 700ish but it didn't surge at all. Then after it was warm I blipped the throttle a handful of times and it started surging after a while of doing that.


At this point I'm out of suggestions - going to take it to the indy to have a smoke test done.

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2003 3.0 5MT Topasblau
Purchased in 2016 and sold in 2024
2012 35d Platingrau