Some common things to check when a car's engine does not turn over include the battery components, the timing belt, the fuel level and fuel injectors and to look for moisture inside the distributor cap. On vehicles with carburetors, check to make sure the choke is not stuck.
Check the battery cables and terminals for corrosion or loose connections. If the cables are too corroded, they should be cleaned or replaced. Another common failure point is a loose or damaged timing belt, which would cause a vehicle to not start or die quickly after starting. If the car does not start on damp or rainy days, check beneath the distributor cap for any moisture, which would inhibit the distributors from properly firing.