Check if you have spark! This can be tested by taking a wire (pref cylinder number 1) and taking a old spark plug and grounding it. It only will take a few seconds of cranking. If that doesnt work then on the passenger side of car towards fire wall will be a sensor called a crank shaft sensor if your car doesnt have a distributer. Unplug the sensor if you have one clean in with electrical cleaner then plug it back in.