1993 s10 4.3 tbi z drives fine at first then stalls when when i reach 35 mph. when i let off the petal a lil bit it normal what could me causing this.

 

I had the same problem with my 1999 Blazer w/4.3. First I replaced the fuel filter which was very plugged up(tested it by trying to blow through it). Probem continued, then I realized that the fuel pump had failed due to the restricted fuel filter. Solution was to replace the fuel pump and replace the fuel filter more often. Not that difficult but way more expensive than if I had known to replace the filter about every 20,000 miles. The original lasted 70k before it killed the pump. Try replacing your fuel filter first.