1995 Nissan Maxima Starting Issues

At times when I turn the key to start the car I get nothing. I continue to crank and it catches at non-specific times. Recently, when it does crank, the engine slows like it's in the dead of winter. The engine seems as if it's not getting enough power to turn over. I replaced the starter in it about a year ago, as the old one was burnt out. I was thinking that it may be an electrical relay, either in the ignition switch or the starter itself. Any help would be much appreciated. Thank you.