I have a 89 camaro RS with 5.0 TBI, it will start but after you shut it off and wait a minute then it won't start, then you have to let it sit 15 minutes to a hour then it will start, it has power and I replaced the neutral safety starter switch, and still does the same thing. Security light and service engine light comes on when the key is on but won't start until after you let it sit, please help

 

If the security light is staying lit, you have an issue with the VATS.
My ign cyl went bad, in my old '91, reading the key resistance so, I bypassed it after it left me stuck, once.