No start

ok so yesterday my 1990 lumina wasn't starting after i shut off the engine. So i bought a new battery today and put it in. it started ok then I let it warm up (idled for an hour) it never stalled or ran badly. then i shut it off. 2-5 minutes later I went to restart it and it just cranked and cranked. It has a new battery,alternator,plugs,wires the only thing thats original is the STARTER. is it possible that it is the starter?

If it cranked or spun over then the starter is working, no? Do you have spark at the plugs, 37 psi fuel pressure?

fuel pump is a week old. I brought it tothe mechanic toay and he said it was the starter so he replaced it and now everything is good again.