Dougs951S

I've got a question concerning the fuel vapor purge system. I'm not running a factory BOV or an ISV so in the interest of easing fabrication of my air intake pipe and saving weight, I'd like to also delete the connection for the fuel vapor purge and vent that to atmosphere. Can I leave all the equipment in place temporarily and just plug the line that would have gone into the J boot, and then throw on a vented gas cap? I would be gutting the system entirely eventually.

Dave W.

You can put a cap on the J boot fitting, but leave the vent hose open. This is the path that allows expansion/ contraction of fuel vapors in the fuel tank due to temperature changes.

Dougs951S

I actually wont be running a J boot in the traditional sense, just a pipe with a single bung for the AOS straight into the turbo inlet. I just wasnt sure if it was ok to simply leave the fuel vapor purge line uncapped and open. Should I just tuck it back by the firewall, or tuck it down to vent into the driver side fender well?

Does anybody know the ID of the AOS to j boot hose so I can weld a bung on?

zerMATT951

I disconnected mine, but could smell fuel vapors after. So I plugged it and drilled a tiny vapor vent hole in my gas cap instead.

reno808

I capped and deleted everything. The only thing i vented was the tube that comes out of the gas tank that goes to the front of car. I put one of those cheap vent filters from autozone by the T-Bars. Never smelled any gas since.

Drilling your gas cap is dangerous......

zerMATT951

And venting fuel vapors under your hood isn't...

Scott H

No one is venting fuel vapor under the hood. It should be back by the torsion bars. The Euro cars ran without the fuel evap system and just vented the tank to atmosphere out the back.

Edit: PET diagrams to show the difference.

Dougs951S

Thanks Scott, I'll probably vent the tank by the TBs and leave all the equipment in place under the hood for the very immediate time being. I kind of assumed it was that simple.

reno808

umm if you read my post that's not the case. i am venting the vent tube. LMAO.
Sure let me drill the gas cap. I hope you dont corner hard when you fill up your car hahaha

reno808

YUP exactly thats were my idea came from

Dougs951S

Thanks Rob, that was the one I had in mind but couldnt remember the name! I dont have the key to my locking cap anyway so its of no consequence to me.

zerMATT951

The factory option is a one-way valve, not a paper filter from the auto parts store.

So you really think that fuel is going to come gushing out of a 3/32" hole in a gas cap if the car is inverted.

chrenan

I use the stant vented gas cap Doug. Seemed like the cleanest solution, I've had no issues with it.

Mangonesailor

Lockable? I found a place that sells Pure 94 octane so I'd really like to keep in my tank.

chrenan

Mine isn't, car goes to the track and back and lives in a locked and alarmed garage.