Certainly have to check the basics, like accelerator pump shot, before moving on.

I'm not as familiar with the later system...have worked on '77 and '78 models. But they used a ground wire on the throttle stop so the system knows when the throttle is closed. Also, they have a throttle position transducer (TPS in modern terms). If accelerator pump action seems good, checking the condition of these may help. The computer can't react if it doesn't know the throttle is moving.

If you have a set of '83 factory service manuals, they're sure to be of help. If you don't have a set, and get stuck, let me know. I have a set, and can check through the diagnostics for you, post some photos of those pages, etc.