Wont start at first started for a few seconds but then turns off . will not stay on

See if the security light stays on when you start it.
If it does, this is a SKIM module/Security Key problem.
You need to service that system.
You can have it serviced at the dealer and probably the skim needs replaced...
Or you can remove the skim on the bottom of the steering column and order a new ECM for the car having it programmed with your vin number.
Do not reinstall the skim. Just start the car and let it run till the security light goes out. if it does not, cover the lamp or remove it.
The car will run permanently without security keys.
You can use all the dummy walmart keys you can cut for it.
No more $200 dollar transponder keys :D

If I may suggest, you may want to check the ignition coil or check your fuel pump. the most likely cause is that you have a bad pump, and it stopped working....causing you to only use the fuel in the lines and then the engine shuts off due to lack of fuel supply. have someone get close to the gas tank and listen for the fuel pump to cut on. Beforehand, it may be wise to check the fueses and relays for the pump.