I have a 1981 Dlx 4x4 pickup. Engine compartment is all stock, california smog spec 22r. When the throttle is gassed, the idle will settle and stay at about 2000rpm. When you stop, it will take about 5 seconds to go back to the normal 700rpm. If revved to say 4000rpm, it will go back down to about 2000rpm and stay for a few.

I've tried two different carbs, can't find any vacuum leaks, and the throttle linkage and cables are smooth.

The carb I have on now is brand new. Besides this issue, the truck runs and starts great. IT will hold very steep angles without stalling and has great response on the entire curve.

Of note, the VCV on the side of the carb is suspect and makes a farting noise when accelerating. Toyota no longer carries the part.

Any suggestions where to look now? and how the heck to I check the function of the dash pot?