Good Morning Guys, Im experiencing a hard time with my Z at the moment. I own a 350z 2003, and recently a couple of weeks ago, suddenly the car started to delay for startup, it starts but takes around 10 seconds. When you give ignition with the key the engine turns fast which lead me and my mechanics to blame probably the crankshaft sensor. So, we placed the scanner to double check and just as we thought it was detecting the crankshaft sensor, and bank 2 camshaft sensor also. So, I bought all 3 sensors brand new from the USA ,oem and brought them to my country. We placed both cams sensors and the cranks sensor also,all new, and the car is still having the same problem. We placed once again the scanner and now it detected the crankshaft still, but this time 2 new codes, which mention problems with the immobilizer and antitheft system. At certain point we thought it was the immobilizer with computer that is not working properly, but a car electrician told us that if the immobilizer doesnt works, it doesnt works at all, it does not allows you to turn on the car even with a little dificulty. I want to mention my Z is giving me a headache only with that problem, everything is running cool besides that. The service engine turned on as well the safe mode which doesnt allows me to rev above 4k. My engine has 50k miles driven only. My apologies if i missed any step in posting this thread. I am really desperate for help as I dont want to be jumping from one mechanic onto another. Any suggestions will be deeply appreciated, i dont know what to do. Thanks guys!

 

just a couple random thoughts:

maybe check the battery?

check grounds?

shots in the dark......good luck Man!

 

Try this:
Clear fault codes
Disconnect the battery for 2 hours
Reconnect the battery
Start