Funky 1.5K idle - Problem 2 of 2

[Stoly]

I also have another problem with my '92 85K-ish 1.6L. I've done several variations of searches and according to all of them I just need to randomly replace all my sensors, etc. I'm not a big fan of just replacing shit until a problem goes away...

Completely random change in idle with no indicators as to why. I travel for a living and have come home after six days on the road, start it up, and it acts normal. 1.5K-ish idle/choke and then settles into the normal nice sub-1K idle. Drive around for a bit and suddenly I have a "perfect" 1.5K idle as if choke never went away. That would be an easy indicator except that after a while it goes to 1.1K with consistancy. Sometimes it eventually goes back to a sub-1K idle, sometimes it doesn't, and even worse, sometimes it goes back up to 1.5K. Even more frustrating is that sometimes it doesn't happen at all for days at a time.

Thoughts?

[1vicissitude]

First guess, idle air control valve. Do you have the one from scrat you can try swapping? Its not to hard to get too.

Also, does the car have AC?

http://clubroadster.net/vb_forum/showthread.php?t=45654

[★ revlimiter ★]

They indeed go bad. I had one go on Sharka a few years ago. I swapped in a junkyard unit that I'm still using to this very day.