I put a rebuilt starter ran fine 4 a week now it wont start fires intermittently

Hello, when you say it "won't fire", are you saying the engine cranks without starting, or the engine will not crank? It sounds like cranks without starting, from your description, which would have nothing to do with a starter motor. It would be to do with engine performance, such as ignition spark, fuel delivery, engine compression, engine timing, air intake or exhaust flow. Hands on testing is needed to determine what is going on. www.repairpal.com/repair-shops