You must do better than that. You join and make one post: "Running fine and now...."; that is not going to get you very good advice.

We are not standing next to your car, we know NOTHING of the car or you. How about telling us:
... about any recent work done on the car.
... any warning lights illuminated on the panel?
... if it REALLY ran fine since 2005 (or when ever you bought it, and just when was that?)
... how many miles on the car.
... do you store it six months a year and if so, how long has it been out of storage.
...What you do to prep it for storage.
... how old the battery is.
... do you maintain it or just drive it and have the oil changed every five years or 100,000 miles? (I'm being sarcastic, but you get the idea.)

WIthout that, I'd say its the cam sensor or crank sensor or fuel filter/regulator or a rats nest in the intake or contaminated gasoline or bad throttle body, MAF/IAT, spark plug cable, coil pack or head gasket.