Other things such as broken cam belt can also allow cranking and starting.
Ideally have a scan for fault codes run.
Is the engine light on?
Same thing happened to my wifes car. Same year, same car. And for the life of me I can't remember the exact name of the part. Its the electronic part underneath the three coil packs. Take the coil packs off and replace electronic plate underneath. Sorry I can't think of parts name, sucks to get old.
If the security light is off, check for fuel pressure and spark. If you're not getting spark, suspect a bad crankshaft sensor or chafed wiring going to the sensor.
You should definitely check your timing belt.
My 08 Grand Prix died on me this morning. I was at a stop sign close to my house and it just stopped running. It will crank but will not start. We got it back to the house by pushing it. I would like some idea on what the problem could be. As I said it will crank but will not start I have all power in the car but just will not turn over.
