It is either the fuel system or the ignition system, I know that much from your description, but it is hard to say without more information. Most likely problems would be fuel filter, fuel pump(when you turn the key on/engine off listen for a humming noise, that is your fuel pump priming, or ignition module, or the distributor itself. Also it could be as simple as needing new plugs, or a new rotor and cap. Pretty vague answer, huh? It's hard to work on cars over the internet. Good call on the IAC Razor guns, that could be it too.