I got a 2005 g35x sedan.
It take couple of extra seconds to start my engine. The engine starts all the time but I would have to hold the ignition for 3-5 seconds longer than normal. It needs couple of extra cranks to get the engine started.

I had my battery checked out by auto-zone and they said it was fine.
What could the problem be?
thanks.

 

your camshaft sensor is going bad.

 

cant be my camshaft sensor. I replaced both myself during the summer.

Im thinking its something electronic because whenever I highbeam, lower windows, or do something with the power the rpm would drop 100rpm.

 

possibly be poor grounding contact at the battery. check the negative cable. but you should also use a multimeter and check your cars alternator current while it is running at idle speed, and check the battery voltage while the car is off. weak alternator would give similar symptoms you described.