I currently own a 2004 g35 coup all the bells and whistles. 177k on engine . it was running fine until about 3 months ago and it started dieing out on me and It didn't matter highway city and it only happened once in a while so I keep driving about 2 months and finally . I decide to chance the fuel pump and electronic throttle body and sensors cam shaft and crankshaft
it runs for about 5 miles and it does it again now I can go 5 miles and wait with a dead car till im able to start it with jumper. Now my mechanic says its the high pressure fuel pump under the hood. Please im going crazy replacing all of this I need help I thank you in advance Don g35

 

It could be a alternator (are the pre-set stations on your radio missing)? If that is the case it's your alternator. Could be something lose like the Mas AirFlow (MAF) sensor causing it to shut off.. Are you seeing in CEL's on the dash (is the dash lighting up like a Christmas tree). You could have trash in the fuel line or in the tank... it could be a lot of things. I'm just giving my two cent.

 

DonR13, what country do you live in? I know some of the G35 sold in Australia were available with a direct injection engine that is not available here in the USA. Unfortunately I can't be of much help with your troubleshooting because we literally don't have that VQ30DD engine here in the US.

If you do have the VQ30DD engine (check the sticker in the engine bay or the driver door jamb, both will have the engine listed on that sticker) then it is definitely possible your HPFP failed, one more reason I dislike direct injection engine.

Does the service engine light turn on? If so what codes is it throwing?