I turned my car off to go into the store when I came back out it wouldn't start. acted like it wasn't getting fuel put more gas in it still wouldn't start. someone said it was probably fuel pump so I put a fuel pump on it then a fuel filter, then a crank shaft censor, still won't start, someone then told me it was the theft system so I tried two different methods that two different shops told me to try neither of the two worked, now someone says it could be the timing, can anyone tell me how to check the timing, or possibly what else could be wrong with the car. I need help bad