thoughts on high-idle

[JerryC]

My old school brain says... Check the all the mechanicals from your foot to the throttle blade.
Is the TB clean?

Does the throttle blade return to base position? Heating the engine could be causing a slight warp and/or binding in the TB or linkage/cable. Has somebody done the zip tie mod to your gas pedal/ throttle cable?

From experience, when changing my 02 sensor, I saw the connector was crusty. Bad enough that I probably didn't need a new 02 sensor. But it was already replaced and I just cleaned the connector and left the new one in there.

Checking connections doesn't cost anything but time.
Does it have the ground wire from the engine to firewall, this commonly gets left off during engine swaps, cyl head work.

 

[Pix3L8]

My old school brain says... Check the all the mechanicals from your foot to the throttle blade.
Is the TB clean?

Does the throttle blade return to base position? Heating the engine could be causing a slight warp and/or binding in the TB or linkage/cable. Has somebody done the zip tie mod to your gas pedal/ throttle cable?

From experience, when changing my 02 sensor, I saw the connector was crusty. Bad enough that I probably didn't need a new 02 sensor. But it was already replaced and I just cleaned the connector and left the new one in there.

Checking connections doesn't cost anything but time.
Does it have the ground wire from the engine to firewall, this commonly gets left off during engine swaps, cyl head work.

It's funny you said "heating the engine" I happened to light my entire engine bay on fire last summer from a faulty fuel line. That being said everything except the throttle linkage was replaced under the hood, it does look a little...crusty. If I just unhook the throttle cable from the TB and let it idle I should be able to test if it's playing a role in my high idle I would think. And yes all my grounds are connected.