Hey guys... I recently got my fuel vapor issue at the tank fixed thanks to a new Oring, and a couple new pieces of hose on the tank. Since then, I am getting a lot of fuel vapor smell from the line that used to go to the carbon canister. I don't remember it being that strong when the Vg was in the car, but the LS causes the underhood temps to be consistently higher, so I smell it a lot more. Would it be ok to put a ball check valve in a piece of line and route that vapor back into the intake when the car is running? That is what the carbon canister did, so I would assume the answer is yes. Anyone have any input on this?
The stock carbon canister was vented back in to the inlet at certain conditions. Some cars employ a solenoid valve to purge the canister and others a positioned port in the TB so the can would only be purged at *blah* time/throttle opening where the vapours wouldnt make any appreciable difference to emissions. I see no reason you cant do that using a check valve and a restrictor to prevent vacuuming the tank to buggery!!!!! E
I hadn't thought about the amount of vacuum that would place on the tank to be honest. I am going to make an enclosed airbox sometime soon, I could just dump it into the air box.
Yer you can do that but my problem with that is if you get a backfire or something on startup, you might have the right air/fuel mixtures in your airbox to make a pretty decent bang!!!! The vapours in the canister and purge system are sufficiently rich enough not to be a problem. You options are to vent the tank somewhere or into the inlet manifold via a restriction. Thing is, you still need an atmo vent. Somewhere for the tank to get its air in, which in turn is going to let the fumes out unless you fit a small check valve to seal it off and any residual tank pressure is directed into the engine on shutdown!!!!!! This is how the stock system should work anyway. My view is to fit up and connect the carbon canister as its intended. Or alternately, use the manifold line with restriction and fit a check valve on the tank atmo vent which should connect to the inlet somewhere between the air filter and the engine TB. lets clean air in but nothing out or simply just route the tank atmo vent to well underneath the car. Underneath the car is ok as the fumes are heavier than air and as the tank heats and vents the fumes should just fall down and just dissipate away. E
Talk to Kurt aka lysergic or the forum he has a l98 with a turbo and he runs a carbon cannister system from memory with no smell issues he maybe able to point you in the right direction
I am looking at putting an industrial pop-off (pressure relief) valve that opens at like 3 psi. I don't want to put a carbon canister back on it.
Then I'd just use a simple checkvalve found on a zillion cars to prevent pressurising and run a small ID line to the manifold somewhere and fit a small restrictor in there. Just big enough to allow some air movement on vac. Easy as and no smells when driving. E
