First: If the engine turns over, the starter is doing its job. There can be a wide array of things causing a vehicle not to start. First and foremost is to reboot your systems computer. This is done by disconnecting negative battery cable, wait a couple minutes and reconnect.Next,The two things to check for is fuel and spark. If you have fuel getting to injectors or carburator then it may be you are lacking spark. First thing to do is a fuel check, turn key on and listen for a motor hum noise from the back of vehicle, or have someone stand at rear of auto with trunk open to listen for this hum. If you or helper hears hum, and it should stop after a few seconds then you know your fuel pump is working.If no hum check fuse to see if it has blown, if it has blown replace and start car,let idle if it starts and run for a while to see if fuse blows again.If it blows again it is obvious that there is a problem causing pump motor to over heat. Also check fuel pump relay if there is one on your model. Second you must determine if fuel is being delivered to the injector rail. Caution this can be dangerous and should not be attemped by someone with little mechanical knowledge. If fuel is getting to rail, then proceed to spark analysis. Start with coil. Remove coil wire from distributor. with a non electric conductive pliers hold the brass receptor has close to coil distributor receptor, there should be a tiny ark (spark). If you are getting electrical current to distributor your next analysis is your electronic ignition module. You can remove this and take it into a parts dealer that offers free testing. if this is working properly and you have fuel, then your problem is out of your hands and you need to have your auto put on a scope for testing. Your problem can be anything from malfuctioning injectors, low fuel pressure or a wide array of electrical problems. I realize this sounds expensive but trial and error such as a new starter is not cheap. The price for testing usually runs about a 150.00 dollars per hour, however i have found it takes about one hour for most problems. Some mechanics offer free dianostics if they get the repair job.