I have a TurboXS BOV on my car and whenever I shift under boost I smell fuel. The scent is there for a few seconds and then it goes away till my next shift under boost. I believe there is a relation there, but wanted to confirm my understanding.

This only happens when shifting under boost. I wonder if I can move it lower in the engine bay so the fuel smell doesn't intrude into the cabin?

 

You shouldn't have any fuel smell regardless of what BOV you have. If you smell fuel under boost it is probably a small leak, as you boost your fuel pressure rises and reaches a point where the fuel finds a way out. You should look into this as I wouldn't want to see another FD lost to fire.

 

It is most likely your fuel pulsation dampener or a clamp or hose. I would invest in a fire extinguisher immediately and put this on the top of my "to do" list if I were you.

Shawn

 

I think you guys read it wrong...

There is NO fuel smell *while* I boost. Scent of Fuel occurs AFTER I shift if the car is under boost and the BOV does its job of releases excess boost.

The car is solid, everything works perfectly Just wondering about the relation between the BOV actuating and the transient 2-3 second scent of fuel. And yes I do have a fire extinguisher.

 

From what I remember, if it was the FPD you would be able to smell fuel strongest at idle, not just after boost. If you search I think I saw a thread about this before, and one of the possibilities was a faulty solienoid or something. I have the same issue, actually.

 

It cant be coming from the BOV. It releases pressure between the turbo and the BOV but doesnt create a vacuum on the intercooler and manifold to pull fuel vapor back from engine.

I will admit my knowledge of the stock fuel system is limited but it should be similar to my aftermarket system. If you are boosting then the fuel pressure is increased - at this higher pressure leaks and loose fittings would become more apparent. Smelling it at a certain time can not be trusted in diagnosis because there is no way to know how the vapor propagates to your nose.

The fuel system isnt that complicated and there are several tests outlined in the manual to test the system. I suggest you turn some screws and check it out this weekend - I can do a search and start pulling up all the pics of 3rdgens that have burnt up from fuel leaks if you need more motivation.

Shawn

 

As shawnk says there is no fuel present in the charged air from the turbos to the manifold. The BOV is pure coincidence. I would be looking for issues in the fuel system as I am one who had a line rupture and set his car on fire. Mine was saved because I carry an extinguisher and am insured. It wasn't cheap.

Check the lines, injectors and FPD for certain. The time to check it is now, not after it catches fire.

 

Not sure if I follow your line of thought. My aftermarket BOV is not on the intake side like I see some of the Greddy and HKS BOVs mounted. It is off the side of the turbos. Not sure what you meant by releasing pressure betw/ turbo and BOV and creating vacuum...

The BOV relieves excess boost (air) from the turbos. In stock configuration, that gets fed into the stock airbox and recycled back into the intake tract. When the car spools and the BOV operates and makes that woosh sound, the excess air is vented to the atmosphere. I believe that excess air contains vaporized fuel as well and I believe that is what I smell under my conditions. But I'm not sure and that was what I was hoping someone here could clear up.

I believe my fuel system is fine. I've checked it out pretty thoroughly and there are no leaks that I've seen or smelled and all hoses look good. The vapor propagates to my nose the same way fresh air comes into the car. If I have my recirc on, I don't smell anything b/c its taking air from the interior of my car. I can steady state accelerate under boost and not smell anything.

Hmm... I wonder if I didn't just answer my own question there...

 

Damon - I'll check it out again this weekend. Its just so weird that the correlation isn't there. Trying to fully understand this.

 

There is no fuel ever present in the BOV regardless of where you have it installed. The injectors release fuel directly into the intake ports; all of the air the BOV vents is ALWAYS behind the the injectors, so no fuel is ever present in the charged air until you practically get completely inside the motor.

The BOV merely vents between the turbos and throttle body. Since there is no fuel present between the turbos and throttle body there is never fuel in the BOV. Even if someone got creative and somehow believed there was a vacuum going through the intake tract (and it would have to be backwards; flowing from motor to turbos. That would never happen) and somehow sucking fuel out, it would have to get past the throttle butterflies. Ain't gonna happen. No way no how.

Check the fuel system.

 

I understand what you are saying, but it is physically impossible for that to happen. There is no way that fuel is finding its way back down your intake tract, through your intercooler, and back to your bov.. especially with pressurized air in there. It's something to do with your fuel system.

 

OK. I understand now how this works. Guess I have myself an issue that needs addressing.

Lines, FPD, injectors... Anything else?