Cold starting

1994 buick skylark 4 cyl.
All major ignition components have been replaced
In warmer days it started fine now in single digit temps, it will fire for a second, stall. To start after that involves several attempts with the peddle depressed partialy. Run stall over and over. Finaly start and hold peddle a minute, after a noticable change in engine, it runs fine. Untill it sits over night. Also fuel filter changed, injecters cleaned, with the machine, not gas additive. Also if related on ocasion severe hesitation, studder off the line. Thanks very much.