mcmastai

That is exactly what I mean, sorry, didn't know there was a difference!

Just thought I'd follow this up and clarify for anyone reading in the future: by throttle cable adjustment I do not mean the tensioning screw with a bolt on either side, like 100% of the other threads on this I've read use. The screw I adjusted actually adjusts how far the throttle plate within the throttle body is allowed to close, by stopping the rotational bracket the throttle cable is locked into from turning. Look on the lower throttle cable side of the TB on the back side (closest to the firewall). The screw will be very small, but it will be clear what it does.

good to hear its sorted - its always the simple things.

 

When you say idle screw -- I thought these went the way of the dinosaurs.  Do you mean throttle cable adjustment?

That is exactly what I mean, sorry, didn't know there was a difference!

Good news everyone! 

The car is fixed. The issue was a previous owner had cranked the idle screw way out, so the throttle plate was being held open way too far. Simply set it back to spec and all symptoms disappeared!

Bump, issue is still there after fixing vac lines. Anyone have any tips?

BUMP UPDATE: Got some snazzy new Vac lines on the way, just have to wait for them to arrive. Still feel like no one else on the internet has encountered this before haha