Car is parked for the winter but it's time to fix a few things.. Unfortunately both my problems I still haven't pin pointed to an abolute fix yet. Hoping you guys might have some ideas.

Car: 2006 Revup 350z w/ replacement engine (oil consumption) and various NA mods.

Problem - Strong Fuel Odor
I've all of a sudden got a very strong fuel odor in the car. Too me it smells unburnt (could be wrong). I've also noticed I loose prime overnight. If i goto start the car cold in the AM it will very rarely fire first go. If I prime the pump a few times it will start like normal.

I'm running Uprev Osirirs but my Tune has not been altered in like 2 years and it always ran great so I'm ruling out that. I also have Left and Right Wideband and my AFR is OK but I have noticed sometimes at idle it will ramp up and down. 13.3, 14.5, 13.2, 14.5 etc etc. This might be a separate issue though. Thinking O/2 sensors.

I've got no visible fuel leaks that I've been able to see. Thoughts on possiblites?

UPDATE. Post 11. I've found the leak. Need suggestions on fix.

 

Did you pull either fuel tank lids off behind the seats to play with the fuel pump or float?

 

I haven't. Do you think the pump might be on the way out? Seems a bit early. Anything I should look for?

 

It's interesting to me that you say you smell fuel from inside the car. If it were leaking outside, you'd probably see it and you should definately smell it.

From the inside, the only 2 places I'm aware of where fuel vapors could seep into the cabin is around the pump and float assemblys. There is an Oring that seals the float assembly and pump assembly to the tank. If that ring or assembly is comprimised in anyway, you smell fumes in the cabin.

Check out some of the fuel pump replacement threads on the boards to see what I'm talking about.

GL

 

Any other ideas? Myself nor the dealership has ever touched my pump. Seems like an odd thing to just go.

 

Do you smell the fuel under the hood, if it leaking under hood, it will smell inside the cabin through the a/c & heater vents. It is hard to see fuel leak because it evaporates very quick.

Well, the fuel line run under on the passenger of the car up through the passenger side engine bay.

Where the metal hard line, connects to the rubber fuel, is on the passenger side, right next to the header. Check if it pushed all the way in, its a "quick connect coupling".

The next connection, is to the fuel rail, it is on the passenger side right behind the intake manifold. Check if it leaking their.


From inside, the fuel pump is under the passenger side cubby, and the extra fuel sensor is on the driver side cubby. Both of which are behind the seats. Check to see if the fuel line is secure and gasket is not leaking.

 

This is exactly what I was looking for. Appreciate it. I'll get the car jacked up this weekend and take a look.

I've noticed the smell is particularly strong if I'm on my knees around the drivers side front wheel well. So i think you might be right that the smell is coming in from the engine bay. I've just always assumed since I can't see it, it doesn't exist but it's quite possible it's evaporating before I can see it like you said.

Will report back once I've taken a look at the mentioned areas.

 

Is your fuel system stock?

 

It is.. Apart from a AAM fuel adaptor for the nitrous and a fuel pressure sender for the guages. Both of which I've checked pretty throughly and can't see a leak.

 

Ahh i see, well yeah, just trying to see if the connection our tight, also, trying get up close and smelling the hoses, it shouldn't smell like gas AT ALL. if it is, it is leaking somewhere.

Also, im not sure if you replace the fuel hose, but if you did, make sure it is "fuel injection hose" and not just "fuel hose".

When I re-did my fuel lines, oreilly gave me regular fuel hose, WHICH should not be used for fuel injection. Over time, gas actually seep through the fuel hose, so yeah, use approve fuel injection hose, they come in the same sizes..

 

Ok so I put some time in this weekend. I've found where it is coming from.

Initially I thought it was my fuel tap, since I had issues with that leaking when I first installed it. That's not the case though. For whatever reason it appears the leak is coming from the area in the red square. I find this odd considering it's an 06 and the fuel rails have never been removed.

Does that area even make sense? It appears to be coming out from under the bolt. If I wipe it all dry then prime the pump that is the first area to get wet.

Thoughts? Please tell me I don't have to remove the fuel rail. For anyone that has removed one and looked at one would it make sense to be leaking there?

 

I found a picture of a stock fuel rail off the car, and from what I can see the only way I would be seeing a leak in that area is if injector #6 is leaking.

Thoughts? If that's the case I'll put it back together and let Nissan deal with it. Powertrain covers injectors.

 

Wish I had more for you but it looks like you're doing a good job so far I would take it to Nissan and have them check it out. Some people don't like dealers though.

 

Really don't understand where it is coming from. It pools on that bolt but if I feel closer to the injector along the rail, dry. Rail to fuel tap, dry (from what I can tell).

 

MIGHT SOUND SILLY BUT, is the Bolt tightened down enough??

 

I've never had the fuel rails off, so I would assume so. But which bolt are you referring to exactly?

It's my understanding the only places the rail can leak is the hole at each injector, and the end where the fuel damper is.

The bolt where the fuel is pooling is just a mounting bracket.

 

Despite getting little help here, I figured I'll keep updating.

Pulled the fuel tap/regulator off and relplaced the o-rings. Re-torqued. Zero leaks. The fuel is still pooling on the bolt though. I honestly think there is a crack in the fuel rail right near the bracket.

Maybe from my solid motor mounts? Even still I've never heard of anyone cracking a fuel rail on a 350z especially a 2006.

 

^sounds likely. as far as im concerned that bolt just bolts the rail itself down. i suggest taking the rail off and having it checked or buy another rail. taking the rail off isnt hard at all. its been a long time since i had my oem rails on though lol.

 

I've got the rail off right now.. I can't visually see a crack in the rail, but injector #6 looks a lot wetter than the rest. I honestly think it's #6 leaking, just don't see how the fuel is making it that far away.

 

ive got a oem fuel rail for sale if youre interested.