i have a 91 s-10 Blazer 4.3 TBI with 146k on it. when i bought the truck a few weeks ago i knew the engine wasn't running quite the way it should but i figured a simple tune up would fix the problem. nope. so far i've cleaned the throttle body, replaced the pcv valve, cap, rotor, plugs, wires, and changed the oil. the problem still persists. when i tromp the throttle it loads up, backfires, and then goes... but if i roll into the gas slowly it doesn't have the fuel loading problem. once i'm accelerating, though, the truck just doesn't have the power it should. I've driven other 4.3 s-10 Blazers and i know what that motor should run like. the motor idles smooth as can be and the problem occurs regardless of engine temp.
