First off, make this a little more clear, did it have the problem before you did the work? If so and this is what you were trying to fix, it sounds like a bad idol air control valve. If the problem was not there before, make sure all the plug wires are installed correctly, all your vacuum hoses are intact, No wires unplugged from mass air flow sensor and such as that. I dought very seriously it is the timing if it hasn't been tampered with. Also, DO NOT attempt to adjust the idol on this vehicle, you will screw it up, it is factory set and no need for adjustment.