Rough idle and acceleration till about 30mph...

I have a 91 S10 that has a rough idle and acceleration until about 30mph. I have replaced the egr valve, plugs, wires, air filter, pcv valve, seafoam thru intake and injectors. Still have the problem. Any ideas???

what motor and manual or automatic? Generally speaking, if you can't fix it with hard parts, you won't fix it with snake oil. Sounds like it could be a fuel problem... have you checked the fuel filter?

Seafoam isn't snake oil and using it to fix any problem that isn't caused by carbon buildup won't net you very much. Does it matter how you drive it? Will it give any hint of problem past 30 or does it go away once you hit 30?