I just got done fixing some issues on a 99 blazer 4x4. I recently replaced my radiator and upper and lower intake gaskets. Ever since then, i have had crank shaft sensor error. Last year i replaced the sensor, so this year i replaced sparks and wires. Still having problem so i replaced sensor again Test drove it and everything seemed fine. Started to park it on the street and it was being real hesitant then a cloud of smoke. Now it will bearly move and there is a knocking sound.
I believe it has to be the crankshaft and/ or timing and sprockets.

Help Please