I've been noticing that after driving my Z home from work and parking it in the garage, a few moments later a pretty strong gasoline smell will be present. The car doesn't really seem to be leaking gas, as I've checked the garage floor and the gas gauge seems pretty normal with about 18-20 MPG mixed with city/highway. Any suggestions on what to look for? I'm coming from a VW/Audi background so not much experience with the VQ's. Relevant mods are a Cobb tune and ExoticSpeed exhaust with I believe high flow cats. Thanks in advance

 

Maybe it has test pipes?

What version of cobb tune? Some are setup for aftermarket intakes, and if so they could be leading the car to run rich, which if you don't have cats you will smell the fuel cooking out of the exhaust after shutdown since you are in a garage. Try it with the stock tune and verify that the car has cats. If no cats, it's normal, nothing you can do to change that.

 

I have no clue what version Cobb tune it is. I know it has K&N Filters so I don't think the tune is designed for the aftermarket intakes. I'll double check with the previous owner, but I'm pretty sure there are no cats or high flow cats. Would leaky injector o-rings cause this too?

 

If you had a leaking seal under the hood the gas smell should be very powerful and you should be able to see where it's coming from, take a look and see. Check the fitting on the right front of the engine where the feed line attaches to the rail, then trace the fuel rails looking for any wetness or oily appearance that could indicate a leak.

Does the car hesitate to start if it's been sitting? If you have a leak on the fuel rail it will lose pressure after a while and will have to re-prime the system first, causes an extended cranking condition until it starts. If it's not doing that it's probably not leaking in the engine area.

Could be a vapor line or leak on the top of the fuel tank, faulty gas cap, etc but most of that would set a P0456 evap leak code if it's bad enough that you can smell fuel.

 

Try a new gas cap, it if doesn't solve it return it.

 

Quick update, the smell is so faint but still noticeable. I opened the hood and sniffed around and it seems to be coming stronger from the passenger side of the engine bay around the air box area. It's probably lower down but it's tough to see anything.

 

Fuel line comes up the pass side, I would look there. Have someone sit in the car and flip the key to let the fuel system pressurize and look. About every 30 you car prime the system.

 

Question for everyone, since it is fuel related. Is the lines I circled in red in the picture the fuel lines? There are three of them, are all three fuel lines? Thanks.

 

I know this thread is pretty old, but yes BakaN20, those are fuel lines. They run up the passenger side of the car into the engine bay.

I still haven't had time to check out my issue but I probably will some time this week. The smell is still coming up when I shut down the car.

 

Could be a crack in the fuel rail, I had that happen to me.

 

Wouldn't that spew gas out? Or was it a leak so small that it wasn't that noticeable?

 

It made a constant drip, I noticed the fuel smell but it took a while to decide if it was from me removing the fuel bucket or not. When I put it together I noticed the small dribble going down the back side of the engine. Kind of scary...

 

When mine cracked I got a gas smell once and a while thru my vents and my garage would smell of gas. It took a couple weeks to find it, I pulled the upper and mid plenum and started swapping O rings on the rail and dampers. I found it when a friend was cycling the key and i was looking at the O rings I just replaced.

I'll try find the post about it, Pchio also had the same problem

https://my350z.com/forum/autocross-r...ml#post9599281

Mine cracked about a year after his.

 

Hmm, that sounds kind of similar. Thank you, I'll look into it!

 

Mine cracked at the same place on the drivers side though. I blame myself loosening those bolts to install my return fuel components. New rail (actually my old one with 150k) is holding up fine at 65PSI (rising rate).

 

I have no clue what version Cobb tune it is.

 

Does anyone know if there is a DIY hiding for removing the plenum? I see a bunch for the DE motors but not one for the HR. I see the six 12mm bolts but do I have to remove the throttle bodies and all of the other connections that go to it? I feel like there should be a shortcut to this that I'm missing.

 

FSM(2010G35>EM>PG#29) states to remove the throttle body. Assuming you do not have a TB coolant bypass, you should unbolt the throttle body(s) from the upper plenum to avoid getting air in the system.

 

Update! So, since the weather was nice today I decided to tackle this thing and find the leak.
It wasn't by the fuel injectors or fuel rail at all.

It ended up being here:






It's hard to see, but its a hard line connected to that blue hose, which runs up to the fuel regulator. After shut down, I barely saw a tiny tiny tiny stream of gas coming out of a tiny hole on that line. WHAT IS THAT!? My question is, how the hell do you get to that line? It's in such a tight spot. It definitely looks aftermarket though (previous owner).

 

Anyone have any suggestions on how to fix a pin hole in the hard fuel line going to the fuel regulator?