why is my car only starting sometimes after replacing battery and starter

What is your question?

After installing starter would not start just made whirring type noise.After moving gear selector a bit it started,was startihg fine after that now does same thing. After having to mess with last night(move shift selector in and out of gear,take key out,just keep playing with it and giving little breaks, not a straight continuos thing)it started after about half an hour. Today it started right up. Have only started once so far. Thanks.