[T2] High Idle

[Lourd Baltimore]

I recently swapped in a second-hand engine for my old 1600 twin port.

The new (to me) engine is fitted with a Weber 32/36 DFAV progressive 
carb.  It runs well other than the engine will sometimes race at idle if
 I let up on the throttle.  If I quickly stab and release the throttle 
it will sometimes return to normal idle speeds.

went to the engine bay and did the same thing by hand using the throttle
 linkage on the carb. If I press and release the linkage quickly, then 
there is no problem. If I press the linkage and let up normally, then it
 hangs at a really fast idle. When it is at a really fast idle, I have 
to press the linkage closed to get it to return to normal idle. 

The fact that the idle seems fine when the throttle is released quickly 
and or pushed home would rule out any problems with the idle adjustment 
screws.
I'm going to look at adjusting the pedal free play first.  I haven't done that in a while, but if someone can point me in the right direction, then that would be nice.

Any suggestions on where to go after this?

Thanks,

Josh
.