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I recently did the conversion to the LS6 valley cover while I was changing over to the FAST 102/NW 102 tb. I did not install the factory PCV valve back into the line that goes from valley cover to the manifold. LS1HowTo says to use the valve, but some other write-ups I saw said it wasn't needed, but that a catch can could be used if necessary. Everything has been fine.
Soon after, I decided to move my EVAP solenoid so it wasn't sitting on top of my fuel rails any more. I rotated it so that it tucks up near the driver fender and like right up by the radiator, then attached some fuel line to weave back up to the intake.
I'm not sure if it's related to this change, but I have the horrible fuel smell every time I pull back in the garage and shut it off. I thought this would only happen if I ran a breather on there and left it disconnected from the manifold. What the heck? Now my wife wants to me every time I drive the thing. Could me not installing the PCV valve be letting fumes escape the manifold without being burnt up, or what? Help.
Could me not installing the PCV valve be letting fumes escape the manifold without being burnt up, or what? Help.
Absolutely, 100% that.
Not sure how yours is, but I left this part just like that with nothing in it and it smelled like crap. I covered it up and smell went completely away.
I always thought it was my cats or the overlap in the cam, but it turns out that I just letting oily fumes out of the heads.
I actually have the GM plug for that in place, so I don't think it's coming from there. The PCV valve would be installed on the short hose coming from the front of the valley cover and connecting to the intake manifold:
That's why I didn't install it like the write up says to do. I wondered if the line I was using to relocate it wasn't suitable for fuel vapors, but it's fuel line so...I don't know.
Since gas fumes are going through it, maybe I need something else? I don't know anything about different hose types, but it's all I can think of. I got in trouble again after driving this weekend lol.
Are you sure your EVAP is turned on in the tune? Most of the time tuners turn off the emissions features like EGR/EVAP etc. What it could be is the pressure in your gas tank releasing through the check valve that hangs down from the tank by the rear. The EVAP solenoid only works while the car is running, so you saying it only smells when you shut it off leads me to think that it's fumes releasing from the tank since the valve is probably disabled in the tune. If that's the case, delete the ugly line and cap the manifold
Are you sure your EVAP is turned on in the tune? Most of the time tuners turn off the emissions features like EGR/EVAP etc. What it could be is the pressure in your gas tank releasing through the check valve that hangs down from the tank by the rear. The EVAP solenoid only works while the car is running, so you saying it only smells when you shut it off leads me to think that it's fumes releasing from the tank since the valve is probably disabled in the tune. If that's the case, delete the ugly line and cap the manifold
That's a good point - I'll have to check in the tune. It would make sense because this started after my build/tune. If it's turned off, then gas could be building up behind the valve and seeping through the line if it's not appropriate for gas fumes. That could be why I only notice when the car is turned off and in the garage. Thanks for the idea!
That's a good point - I'll have to check in the tune. It would make sense because this started after my build/tune. If it's turned off, then gas could be building up behind the valve and seeping through the line if it's not appropriate for gas fumes. That could be why I only notice when the car is turned off and in the garage. Thanks for the idea!
You're welcome! Go for a drive and then come back and open your gas cap and see if a lot of fumes release. That would be a quick way to determine if it is happening or not.
06-27-2016, 08:54 AM
Gas smell - EVAP related 
me every time I drive the thing. Could me not installing the PCV valve be letting fumes escape the manifold without being burnt up, or what? Help. 
