B2200 stalls when i let out choke

I have a 88 b2200. First off the electric choke has been replaced with a manual why idk. The engine runs awesome when the motor is choked but when i open it, it will just die. I have let it warm up for about 20 min or so came back and same result. How ever if i give it gas once i open the choke the engine will stay running, once i let off the gas it will die. Any ideas.

Fixed it...

Tell us how !!!

I re-tuned the carb replaced the fuel filter and adjusted the timing on the truck. I still have some minor adjustments to make but i can get the truck to idle w/o choke. After a while my check engine light went off now it wont even come on. I was assuming it was carb related. but quick cheap easy fix do know why all of the sudden it just didn't want to work right but I'm glad I was able to come to a simple solution just took a lot of tinkering and patience.