Toyota Corolla- starts then dies, low rpms?

Engine Performance problem 2000 Toyota Corolla 4 cyl Front Wheel Drive Automatic 184000 miles i rebuilt the engine set the timing to the right specks and i thought it was the timing but i have already reset the timing about 20 times and i'm still in the same sport where the verblie timing is the dot is facing the exc side they are line up together and the bottom is facing right at zero but the car will start but will not staying running and backfires like the timing is off and the compression is 150 Straight a cross