I agree with dsaul in that I also don't think you understand how limit screws work. I suggest you go back to the manual and try it again. Per the manual step # 1 is adjusting the low limit screw before attaching the cable (which is step 2). Of course we are assuming you are using compatible 9-speed road shifters (ST-4400, ST-R600, SL-7700, SL-R440) that have the proper cable pull for the front derailleur.