I come home and park my 300z, the next morning it won't start. I've got spark, fuel and it turns over well, it just won't start. I keep trying until the battery is nearly dead. I try one last time and the engine will just barely crank, it doesn't start so I release the key and then the engine starts and runs for 2 or 3 seconds and then dies.

Personally I think it has something to do with the security system but I don't know how to by pass it or disconnect it so I can see if it will work.

Does my diagnosis have any merit, and if it does, what can I do? Any suggestion? Thanks for any help.

 

I'll have to think about this one, but if it was your alarm system, and you have fuel, air, and spark, what is it keeping from the engine to not let it start? My viper system only isolates the ignition switch and won't even crank. Just something to think about.