5.7 TBI runs rich, hesitates...

[JCampbell]

88’ K20 Suburban. 5.7 TBI with 125,000 miles on it. It starts fine, but idles with a very slight roughness. Smells like it’s running a bit rich. From idle, when I advance the throttle slightly, the engine will begin to choke and die, but if I continue to advance the throttle it will pull out of it and run smooth again. (This only occurs after a short warm up. When cold , it will advance smoothly) I can bypass this by advancing the throttle quickly, though I sometimes notice hesitation. When the engine is fully warm, it will occasionally die while idling or after being shifted into reverse. It has always started right back up. There is an inconsistent miss at idle speed that sometimes appears at higher RPM.

Any thoughts on this?