You can do your self a lot of good by going from the basics on out, this is the best way to diagnose your situation.do the plugs, wires, cap, rotor, then look into the electrical system, but if you are sure of all that then go on to the idle air system, a leak in the vacuum system will also give you the same results.If you can not find a way to do a smoke test than find some one who can do it!