Is it normal for the nissan 350z hr idle to go down enough as if the car is close to dieing then move back up when starting the car.

 

Have you had your car tuned or anything done to it recently like battery change? Mine will do this when I have the ac on for a while like a week, like when it is hot during the summer always got it on. Then when I turn off the ac when it starts getting cooler out it does what you describe but will even out after about 20 miles of driving. I think the car is changing to not have to compensate for the the ac being on.

 

No, it's not normal. You probably disconected your battery and need to do throttle adaptation procedure. Refer service manual how to do it using key and acceleration pedal. Make sure you did all 3 adaptations in correct order... 1)Accelerator Pedal Released Position Learning, 2)Throttle Valve Closed Position Learning, 3)Idle Air Volume Learning.

 

Hi regarding disconnecting battery do you have to do that all the time I never did it just wondering thanks joe

 

no I have never had to do any of the 3 relearn procedures Micho described when disconnecting battery.

 

Regardless of whether it's common occurrence or not, never hurts to attach a NOCO when disconnecting the battery. Commonly called a settings keeper.... small little 9v battery device that maintains just enough power in the electrical system so that you don't have to "teach" the car old tricks it used to know.

My BIL learned that the hard way..... swapped out his own battery on his BMW.... without a NOCO. Cost $200 at dealer to re-program the entire system.

If he'd asked me, I'da loaned him my $10 headache saver.

 

I think this comment says something more about BMW quality than anything else.

 

How is not knowing how to perform an operation a knock against manufacturer quality?

If you don't know what you are doing you get to pay teh price.

 

Friend's dad had to get a battery tender for his BMW for like $200 also because he "didn't drive it enough to keep the battery charged."

 

@ecab

I thought you hated BMW?

I haven't had an issue in any vehicle I've owned

 

More than likely the OP's Throttle Body is failing if this happening all the time

Very common VQ problem and I had mine replaced back in 2007 from a similar sounding problem

 

This. I bought a reman OEM unit from the dealer for $180 several years back. 30 minute install. And I did not have to do any relearn procedure either, ran like a dream from the get-go.

 

I have a 2003 touring 6spd and it has been doing this for half a year now and getting progressively worse. As of about 2 months ago 7 out of 10 start ups will result in it sputtering around 200 rpm like its about to bog out and then jumps to idle and holds just fine. However 3 out of 10 starts result it dying completely. Only when car has been sitting for a prolonged period of time; every morning and every time it sits for at least a couple hours 3-4 hours. Now there is a very loud whining noise no matter how long you let it warm up after start up for a good mile and then a few after you get a pigeon cooing noise then it all goes away. It has been through summer fall and winter in the northeast and symptoms don't change with weather. If anyone could shed some light it would be appreciated sounds like the OP and I have the same problem local shop couldn't find anything but then again they aren't very reputable.