NA - Fuel tank excessive pressure / venting
 

Read all the threads on MT.NET for solutions. Mostly all NB's have a looped line solution. I have an NA and no canister was in place in the engine bay. The line was capped. I cut the hardline by the fuel filter and considering running a fuel hose past the subframe behind passenger rear wheel. The question is - do I need a charcoal canister ? Can the charcoal canister be lower than fuel tank or should I bring that into a trunk ? Perhaps a line with a breather filter for Venting to Atmosphere is all I need? Not sure if NA solutions were ever covered. Already put a shield on the exhaust under the tank. New fuel cap or drilling cap /gutting the cap?

Anyone have possible suggestion - want to hear them. Thanks all

Do you need a charcoal canister? No. The 25+ year old charcoal probably isn't doing much good now anyway. It is popular for people to delete them. IIRC, you simply loop the lines that went into and out of the canister.

I'm not entirely sure this will fix your excessive fuel tank pressure issue, though. Perhaps someone more knowledgeable will chime in.

I am unsure whether there is both positive and negative pressure on the vent line that starts out with a rollover valve and goes through 2 more check valves (purge) valves. If this line will never see fuel, then i was thinking running a hose and a breather filter and insulation for the exhaust for 24" under a tank section.

The vent line has both positive and negative pressure. One for when you consume fluid and air needs to fill the void in the tank; while other is to allow fuel to expand with temperature. Roll over valve so that both these can be met and incase you flip you don't spill out endless amounts of fuel. I've never thought about the fact that charcoal canisters are lower than the fuel tank. You figure this could cause a bad situation incase fuel ever gets in line, but I take it that's not supposed to happen by design anyhow.