Lately my G upon startup sometimes goes to like 1,000-1,500 RPM then idles down to around 1,000 (normal), but other times it barely goes to 500 RPM and almost struggles to start.

Well tried to start my G today after not running it for maybe an hour. Wouldn't start at all (first time), tried but then battery indicator (charge warning) light came on and nothing happened. I tried again and it didint work. I then unplugged my radar detector from the 12V port and tried again, this time it did start but barely and idled around 500 RPM for a moment before finally going up closer to 1,000 and acted normally thereafter.

Is this likely going to be my battery needing to get replaced? Do I need to goto an Infiniti dealer for thi? (none in my immediate area)

Could my radar detector have sucked it dry? It doesnt run when the vehicles off so I dunno how that could be. But unplugging it seemed to make a difference.

Could this have any relation to my fuel injector? I had similar issue in a previous vehicle and it turned out to be the fuel injector.

Any help appreciated.

 

I'd say you need to Clean your throttle bodies.

If its been more than 2 years or 30k miles do this before replacing your battery.

Your battery can be replaced on your own, you would need to remove some plastic trim.

 

Take your car to any auto parts store that sells batteries and have it tested. A radar detector or other electronic accessories don't hurt your battery.