Wont Start

Did you replace the fuel filter? It may be clogged, preventing your car from getting enough gas to start. Worth a shot if you haven't replaced it recently.

The next thing I can think of is clogged fuel injectors. You should be able to tell if you're getting fuel to the throttle body. Crank the car with the air filter connection off of the throttle body. In between cranks, see if there's a gas smell. You could also stick a paper towel into the throttle body (in between cranks) and see if it comes out wet with gas. Eliminate the fuel system as a possible cause and you'll narrow it down to an ignition problem. 

If you have fuel going to the throttle body, the next thing to try is to remove the spark plugs and see if they're wet with gas or oil fouled. If they are, clean them off and then spray them with compressed air. Re-gap the plugs and replace them. That may do the trick. 

The last thing to try is to replace the distributor cap and spark plug wires. If they're cracked or damaged, you won't have enough spark to have ignition.