Believe it or not i just spent 5 hours trying to fix my friend Nanaki's g35 and spent so much time trying to find a awser that after finding one im posting it here and using his account to do so .
It would crank but not start and its twin turbo so there could be multiple problems, being a ASE certified mechanic i went through every thing, from gas, to air to fuel, and then spent a additional 2 hours online till i found some articles regarding the KEY's lossing there magnetic signiture.

I'm amazed to say that after grabbing his replacement key and putting it in the ignition the car started right up.
put the original back in and would just crank again.
inserted the spare key again just to be sure and VOLA! it started.
so the key losing its magnetic signature should definitely not be over looked

Hope this spares some one a lot of time https://g35driver.com/forums/images/smilies/driving.gif

 

IF any one has had a crank and no start and would like to add there problem and solution that would be great

 

My car is 2003, coupe. Yesterday, it won't start even though the battery is good, and the radio is still play. I will try a reserve key to see if it work today after work. I'll keep you post, and thanks for the post. I hope my car key is the problem.
LaRatta

 

I had that problem before..I've got the flip key, and the chip became loose..after trying alot...that popped into my head...so I opened the key fob and there was the problem..

 

I am guilty of using the key to open my beer sometime. Hopefully it is the key, and can just use my other key. I'll try it and post the resolve.
Thanks,

 

I have this issue consistantly. i have to insert & remove my key 3 times for it to start. And it doesnt always work, Sadly this is a new key, so i need to get another new 1 or research the issue from the cars side