can't start engine after replacing cap, rotor, wires, and now coil.

What is your question?

I know if it is not broke don't fix it. But, I bought the 94 tracker, it ran well, but a little rough. so, i put new cap, rotor, wires,and coil in it and now it sputters, idles rough for a few seconds and will not stay running. I have gone back through it putting all the old parts back in it one at a time and taking them back out with no improvement. I now wish I had left well enough alone... are there any tricks i should try? how do i check codes if it is not running?