If the key has to be held to keep the car running then the ignition switch is most likely going bad. On some models the switch can be easily replaced. On others the switch removal can be a large task.
==Answer 1 == Sounds like the ignition switch is defective.
Bad ignition switch?
When the key is in the "start" position all accesssories are designed to be "locked out" to concentrate all the available power to the starting circuit. How about the "on" position - do accessories have power at that position? - if not could be a bad ignition switch
you simply get in car with door shut, turn key to "dash lights on position", hold odometer reset button in, then turn key to full ON position"headlights on" and hold for 3-5 seconds. light should be flashing. turn off then start car--done.
Get in car, close both doors. Stick key in and pull it out three times. Third time leave key in hold down the passenger side door lock down in the lock position. Turn key forwards and backwards not starting it and then take the key out. You should be done.
Have you tried changing the ignition switch?
turn the key from the off position to the on position without starting the car 3 times, finishing with the key in the on position but without the engine running. this enables the check engine light to display any engine fault codes.
Try turning key to 1st (unlock) position without starting vehicle, then shift to neutral
Place the key into the ignition. Turn the key to the auxiliary position, without starting the engine. Keep the key in the auxiliary position for 30 seconds. This should reset your antitheft system.
There should be a button that says erase. Hold it down for a second and it should clear them. Have the key in the on position with the car NOT running.
To disable a 2002 Hyundai Elantra alarm system, put the key in the ignition. Turn the key halfway ensuring the car does not start. Leave the key in this position for 10 minutes before starting the car.
To reset your car's security system, first, make sure all doors are closed and the key is removed from the ignition. Insert the key into the ignition and turn it to the "On" position without starting the engine. Wait for about 10-15 minutes until the security light goes off, then turn the key to the "Off" position and try starting the car again. If issues persist, consult your vehicle’s manual or a professional for assistance.