Hi everyone,

My 04 350z has about 60k miles on it.

She usually behaves quite well to be honest, however, a few weeks ago the gas guage decided to lie to me, normal, but this time it was much worse and the car ended up running out of gas.

Anyway, I put some gas in her and some additive while I was at it. Everything was good, a few days later I noticed that *sometimes* when I start her up she acts weird, like she is losing power and even sometimes will turn off. If I start her back up she turns over again no problem. Once I am moving there is no issue, no problem at stop lights, etc. Just the initial run.

I also noticed that when I first start the Z she will idle high, around 1100 rpm for a few minutes. After that she drops back down to normal and has no more problems.

For the first issue I think maybe there is garbage around the gas pump or gas lines are dirty since it ran dry she probably sucked up a bunch of garbage. Not sure what the ideal solution for that is...

For the second rough idle at start (I live in a tropical climate by the way) I assume it's possibly a PCV issue or does anyone have any ideas? Recently went for routine inspection and did not have any issues, also did a compression test - all was good.

 

I highly doubt the tropical climate you live in causes any issues what so ever so we can throw that option out. I would say your Z has a stomach ache after taking in some bad gas or something else possibly harmful to the motor. At 60k miles I also doubt your gas lines have gone bad already, you are pumping 93 octane over there right? The high idol upon start up followed by shutting off sounds like a symptom of a vacuum leak. Check your MAF just in case. Do you have any check engine lights btw?

 

I stay away from additives; in my experience, they cause nothing but problems.

And stop referring to your car as "she" or "her." It's painful.

 

I would clean the maf and air filter those can cause rpm issues if not looked after. I also would always use 93 octane and not add anything unless you are planning to store your car.

 

Thanks everyone.

Syner - Hah! It's a cultural thing. My dad always referred to his BMW's as his girls, guess it just stuck. Lame habit.

Gas - we don't have 93 octane in the country we only have 91 which is the highest grade. I always pump 91. A month ago, someone, not saying my girlfriend, pumped regular in the Z. So, I figured that would be out of the system by now, maybe not?

The RPM being high at start - turns out that is normal, for the first 1-2 minutes it's normal for the RPM to run 1500-1800 rpm, I read that yesterday.

So my only issue would be that the Z sometimes acts like it wants to shut off when I first start it, I suspected MAF/air flow issue too. I am going to look into it, and yes it's throwing a CEL at the moment, I am just waiting on my friend to return my scanner to check it.

 

It's all good, we all have our little quirks. Running one tank of regular shouldn't cause any issues.

Clean the MAF or pull the code. Best of luck.

 

Syner thanks. I will clean the MAF and pull the code this weekend and see whats going on -- will keep you all updated!