This morning my son said the car will not start, until then my understanding has been that it is running well. I checked the oil level, which was fine. The engine turns over when I try to start it. It sounds like the spark plugs fire once or twice then the engine just turns. After several attempts, I faintly smelled gas, so I assume that it is getting fuel. I had to leave without checking the air filter. My assumption is that I have an ignition problem. The car has the 2.5 liter engine. Other than the spark plugs and wire connections, what common things should I look to fix?