Is nissan 350z 2004 have a chip in the key some time car won't start

Hi James,here's what the sensor look's like. 5results for 2004 nissan 350z throttle position sensor .it's in the throttle body.

click on link to see. Nissian Crankshaft and Camshaft Sensor Recall Nissan 350Z Common Engine...

Needs to be checked for leaks and recharged.
GL,
TD

Drain all the fluids replace them with new fluids then replace the cars computer that should get it running.

Remove inner panel carefully. find 2 black circle stickers and raise glass to access 2 screws holding glass. Door vent does not need to be removed.

60,000 to 80,000 miles

I am not aware that there are indeed two thermostats on the 350Z. I would be more suspicious of the water pump causing the overheating problem. Is the water pump leaking? Leaking is a sure sign that the water pump is defective, but I have seen water pumps that were not leaking, but were still faulty because they were partially clogged up. Anyway, hope this helps and best wishes.

after i replaced the battery in my 2003 350z, it would stall immediatly after i cranked it on unless i gave it a little gas. I fixed this by cleaning the MAF and throtle body valve. Total supply costs were $15 and took about 20 minutes. My Z is not only fixed but runs smoother and cleaner.

14 volts is about right.  Have you had any starting problems?  Are your headlights dim?  Does the gauge move when you turn on the headlights and the blower motor?  I also have a 2004 350z.

install a free flowing aftermarket air intake kit, like one from K&N corp.