[86-C10-V6]

If I understand the problem, your choke is closing off the air supply to much and causing the engine to choke off with too rich a fuel mixture. You are holding the RPMs up with the gas pedel to prevent it from choking off.
If this is the case you need to adjust the amount of spring tension on the choke and that is done by rotating the choke assembly cover.
If you look at the choke cover where the electric wire plugs into the choke you should see three retainers around the edge of the black plastic cover that holds the thermal spring against the mechanical linkage.
If these are retainers are screws you can just loosen the screws slightly and rotate the plastic cover to either increase or decrease the rotation of the air valve. I believe rotating the cover clockwise will decrease the choke, counterclockwise will increase the choke.
If you do this when the choke is cold, you should be able to see the air valve rotate.
There are index marks on the edge of the choke housing and an alignment mark on the plastic cover. This will give you a relative indication of how much you have adjusted the thermal response of the choke.
If the choke cover is held on with rivets, which is the way it comes from the factory, you will need to drill out the rivets and replace them with screws, these are usually included in most rebuild kits.
As the choke gets older, the spring usually becomes weaker and therefore you get too little choke, if you have too much choke, it has probably been adjusted by someone at some time so I suspect the choke has screws holding the choke cover in place.
Hope this makes since and helps.

P.S. After you have this adjusted, you can follow the RPM adjustment described by Phonex in the previous post. My engine specs call for 2200 RPMs with the choke fully engaged.