Engine stalls when accelerating

I have a 94 Chevy p/u 350 engine, truck runs
great most of the time, but after running for a
while, at red light I can hear the engine
loading up, when I try to go it starts acting
like its out of gas, the cab of truck becomes
toxic with U burnt fuel smell/ exhaust smell. It
usually stalls but always starts right back
up... Sometimes running correctly...
Sometimes it does it over and over. It's not
throwing a code, I'm cluelss