1993 Toyota Corolla HARD 2 START RUNS ON 2 CYL..

IT STARTS ON 2 CYL TURNS OFF...STARTS AGAIN RUNS ON THE OTHER 2 .MY COIL HAS JUICE ON NEGATIVE SIDE TERMINAL WHEN RUNNING ..HAVE NEW TIMING BELT TIMING IS CORRECT ... I SUSPECT POSSIBLE SPARK TIMING WHAT CONTROLS MY ELECTRONIC TIMING