Security light is on but not blinking car light goes on but car will not start

Sounds like a problem with the security. It immobilizes the fuel injector circuit when the security is on.

Try this: turn key to on, and wait several minutes (up to 30 minutes) to see if light stops blinking. If it does stop, turn key back off, then try to start it. If the security light goes off, it may have reset. If it does not stop blinking or staying on steady, the dealer will charge outrageous prices to fix it-possibly over $800. Google "passlock bypass" or "passkey bypass" or "VATS bypass" to see your options. A site called newrockies sells a module (about $200) that forever bypasses the whole security system.

Make sure all of the doors, trunk & hood are securely closed.

i have had the same thing with my 97, turn the key to ON but don't crank engine, leave for 10 - 15 min until the light goes out then crank engine it should start.
GM has bugs with their security systems.

Looks like the TDM/BCM in the security system (VATS/PassKey) is having problems, it's typical on those cars and it can get worse till the car wont start anymore. You can find a great write-up here: http://newrockies.ca , it was the only thing that saved my Park Avenue.

try turning the key on at leave it on till the security light goes off 10-15 minutes then turn the key off and back on and try starting it

turn key from off to the on postiton. does the security light blink?
if so leave in on postition until light stops blinking (10min) then try to start car. may have to repeat process up to three times.
if the security re-learn process works, you will need a new ignition cylinder with security sensor. if not local gm dealer can tell you for sure.

Is your security light on. If your light is on then you have a security problem that means the fuel to your engine is getting cut off. It is a security feature built for the car so no one can steal it all you have to do is tun the key to the on position and wait 10 minutes the security light will be blinking during this time when the light goes off then turn the key to the off position and then try starting the car. This has happened to me you can see it in your car manuel

With the new lock cylinder in it, turn the key on. The security light should blink. Leave the key on for 10 minutes, the security light will quit blinking and go out after 10 min. This will reprogram your security system and the car should start. Also leave a battery charger on it while the key is on, If the battery goes dead during the 10 minute reprogram sequence, you will have to start over again.

there is a computer chip in the lock cylinder that goes bad ,so change the key and cylinder,then leave new key on until the light stops flashing about ten minutes this will set your new key to the security system hope this helps