How to adjust throttle/idle on 1983 ford e350?

It will start up just fine, but after it worms up it will konk… Konk… Konk out. However, if I slightly keep the accelerator pressed, it stays on just fine. I was thinking about adjusting the throttle or idle or choke. Where is it and how do I do it? If there's a picture somehow, that d be super helpful thanks