Yeah, let us know when/if it happens again. I’m having fun coming up with guesses but think there’s currently insufficient information to make a solid call on this.

 

That set is missing the usual culprit in these cases - 'dirty windscreen'.

 

Any thoughts of it being a sensor heat soaking? I'm not sure which sensor would cause that but since there is the belief it might be heat-related it's worth brainstorming that path. Or a dirty MAF sensor that when intaking hot air is losing accuracy?

 

Not for this scenario, no. Dirty/malfunctioning MAF sensor will cause a constant running issue. Most commonly, runaway idle will be caused by an unmetered air leak, like a vacuum leak or throttle plate not fully closing. For idle to rise to 2,500, you need a substantial increase in airmass.

For starters, I might manually check if your throttle plate has any notable friction when the car is fully up to temp.

 

Hadn't driven the car in a couple months because I got a new job and had to move. I'm in Long Beach now which I think is near you @Z_WAAAAAZ ?

Same thing, driving around town for 10min no problem. 50 mile freeway drive and coming off the freeway my idle was at 2k. I put my toe under the gas pedal and pulled it back and the idle dropped to normal. Why didn't I think of that last time? I got in at midnight so I'm not about to start wrenching but I think you were right in your last message Z, throttle plate sticking?

Any known things to do or just start lubing cables/throttle body spring?

 

Hey! Welcome to SoCal man. Yeah, I'm about 30-40 minutes south of you. Small world haha.

Hmm, yeah sounds like your throttle cable may be too tight, or the throttle plate could be sticking. Again, the stock throttle plate doesn't generally have sticking issues, but it's not impossible. I'd start by checking on the cable slack at the throttle body. You want just a little bit of slack on it before the cable starts pulling the throttle open. If cable tension is good, I'd drive the car until the issue is happening, then pull over and actuate the throttle plate by hand to see if it's sticking (probably want to use a rag as it'll be hot. From there, we can reassess.