Many times when a rough idle condition exists, the regulars have suggested
removing and cleaning the IAC valve.  My 1991 Ranger from time to time,
idles rough, and over the past year, I noticed sometimes when I let off the
throttle or push in the clutch to shift, the engine continues to idle high
as though the throttle cable is stuck.

Now, I did already remove the IAC and spray it down liberally with WD-40 or
similar, but the engine still tends to idle a bit rough at times.  Visually,
I couldn't see much carbon or deposits on the IAC itself.  The throttle
cable is also fine as well.  Is there a better way to try and clean the IAC,
I was gonna remove it again and let it soak overnight in a container of
Varsol.

BTW, this truck is off the road now, so it isn't really a big deal that it
runs perfectly.  I'd just like some opinions whether it is worth cleaning
this way or not in case I sell the truck or decide to put it back on the
road.

Sharky