Fuel mixture at idle is adjusted at the back of the IP. Look for a knob which you push in and then turn left or right when looking at the back of the pump. Left is less fuel and right will give you more. Turn it two or three clicks at a time and then adjust using the air ballance screw. Adjust the ignition timing until you get a smooth and consistant idle. It's not hrd to do but then it's not that easy if you are not familiar with the car.

You should also check to make sure the cold start valve isn't leaking and that the warm up regulator is moving freely so that the mixture leans out as the engine warms up.

I have a dealers parts book if you need any help.