I have an 89 IROC 350/5.7L a few months ago it started acting up I would start it drive to wherever I was going then come out and the car wouldn't start again for about an hour or so of sitting the problem got increasingly worse. I have troubleshot and have replaced the PCM, Fuel Pump, Fuel Filter, Fuel Injectors, All new gaskets on the plenum. A year ago it had new plugs, wires, distributor cap and rotor. HELPPP! it still won't do it I'm thinking Catalytic Converter