So basically my 2003 g35 has this problem ever since i bought it where it wont start up when i drive it for a short time (5-15 mins). It cranks over just wont start, after waiting around and trying over and over it eventually starts up again. My friend stalled it the other day after driving for 5 mins and it wouldn't start up took about 5 mins to start it up again. This only happens after short rides never longer rides, and i haven't been able to figure out why it's happening. If anyone knows what the problem could be I'd appreciate the info alot thx

 

My guess would be a cam/crank sensor failure but the 5 minute timer then it works seems REALLY short.

Pull and inspect the plugs, scan it with an OBD2 scanner for any single trip (hidden) codes.