Hey I've got the same thing happening.Runs like = there's a potato in the exhaust pipe. I've just rebuilt this 1.9.
I've checked timing, replaced all vacum = hoses,replaced distributor, cap, rotor, plugs. I am changing the fuel pressure = regulator today. I hope that is it, if not ??
maybe air flow meter (potentiometer).
 
Any help would be greatly appreciated
 
Mike