1999 Chevy Cavalier hard starting

Engine problem
1999 Chevy Cavalier 4 cyl Two Wheel Drive 100000 miles

My car turns over very slowly but always starts. I first replaced the battery to no avail. So I replace the starter but it still turns over slowly. This car runs well once it starts after about 4 or 5 seconds. It acts like its not getting enough juice to the starter any recommendations. Thanks john.