Ok I have a 1999 Pontiac Trans AM. When the weather was warmer started up had no issues. Since the weather has gotten colder it has issues starting. Its cranking up normally just not turning over. It ran strong after getting it started yesterday. But today I got it started after a while, let it run, and a couple hours later, after turning it off it would crank but not turn over. My question is obviously fuel injected engines need air, spark, and fuel. Am I looking at a fuel pump, or am I looking at a spark issue?