[Paulporsche]

As redstroseNic said, you should get your fuel and control pressures, and your mixture measured. In order to get a good idle speed (when warm) which should be about 900, you need to use both the mixture and air bypass screws. You should set the CO% first then use the bypass screw to set the idle.

Offhand, it sounds like your mixture is too rich. A hunting idle is a common symptom of this. It's possible someone set the mixture too high to mask the spark related other issues you had.

Getting the cps measured and the mixture set to about 3.5% will give you a good baseline, and may set everything right.

As a general rule you should always make sure your ignition components are in good order before you do any fuel injection investigation. Check and set your points, rotor, cap, and plugs if they haven't been changed in a long time, or if you don't know when they were installed. The factory wires on these cars last a long time, but not forever!

Finally, as someone mentioned, make sure there are no vacuum leaks. The hoses get old and brittle and eventually leak. You can also get leaks @ the AAR, AAV, decel valve, plugs, and gaskets.