94 Lumina will not start.

In warm days, the car does not start. But on cold days, it will.This might be the problem. I change the starter, but nothing. I changed the solenoid but still doesn't work. When I put in the key and turn it, it wouldn't start. all the lights and dashes light up, the radio works and everything but not the engine. I belive that it does not have to do with the battery because I just got one before the winter. I think its the electrical. I do know it nothing with the cylinder or spark plugs, but the starter and the camshaft. Or maybe the power getting to the solenoid.. If any one can help me. I will have to owe a big thanks to them.

Thank you.

What engine? Does it crank?