1998 Dodge Caravan -132000 klms

I had to replace two tensioner pullys which solved the whisling noise but then it lead to the tensioner it self. When it started acting up after a few day' s the van has been having a really hard time starting up. When it is really hard to start is when it has sat for a few days and it can take a few to many times for the van to start. Then there are times where it starts right from the start. We are on the verge of fixing the tensioner but haven't gotten around to fixing it yet as alot of people are teling me it is the starter. Help me as I am getting tired of then telling me this. My thoughts are it is being caused from the tensioner, Am I right and have you had the same problem?