I have a 93 240sx.Sometimes I have a problem starting it up and ended up getting a jumpstart from someone to get it to start.Went to AUTOZONE & Advance auto to check the Batery and alternator,turn out to be fine and also the starter was just replace last year.all the connectors on the batery are clean.Can someone tell me whatelse I have to know to find a solution for this problem.Any help will be appreciated.