Need help with unknown problem
 

So I bought an '84 c4 last summer and it ran really well until it needed a new starter so I replaced that and it ran fine again. A few months after I was driving it and it all just kind of shut down. The battery turns on,and I have enough voltage,but when i turn the key it starts cranking,then nothing. This particular car im working on with my dad so we're trying not to bring it into a shop,and due to cold weather i haven't been able to work on it. I'm by no means an expert when it comes to cars and I have little experience so I've done about as much as i can,which isn't much. If anybody has anything useful they could tell me I would really appreciate it.

Welcome to the forums. Almost sounds like a loose + battery cable, on the starter or the battery. Ground cable might be a good thing to check and clean also. That's where I would start, hopefully you have a good quality starter.

Welcome to the forum. By cranking and then nothing, are you saying that the engine turns over but stops while you still have the key in the Start position?