I'll preface this by saying that these symptoms started after the car made significant contact with a guardrail on the passenger side. The motor mounts broke/subframe was bent.
Since then, when I cold start the car the idle is around 2000rpm. After it warms up, it will come down to 900-950. Likewise, when cold, if I remove the IAC Valve connector it will drop right down. If I plug it back in, it STAYS down. Turn the car off, and then restart...back UP at 2000rpm...until it warms up.
Aside from subframe/motor mounts, I've swapped...
- Intake manifold
- IAC valve
- Throttle body
- Camshaft position sensor
I found a little vacuum hose under the throttle body unplugged, but reconnected that. I can't find any other leaks. Ten-Ground does not affect the idle.