The # 1 cylinder does not seem to fire, I can remove the plug wire and there is no change in idle. I have verified that the injector, plug and plug wire is working properly by swapping it out with another one. There seems to be lots of spark. No smoke at idle or when revved up. Could it be the cam or the timing belt? There were no other signs leading up to the rough idle, aside from this issue the car is in great shape.