Gary Lewis Posted June 19, 2021 Share Posted June 19, 2021 Hi Gary, Its worth the try. When I got the new filler neck for the gas tank, it came without cap, that's why I bought the one that's on there now. Next month I know more, when I am back in Holland. The filler neck is huge compared to the vent line, and it goes up where the vent line goes mainly horizontally. So I think the fumes will tend to go out the cap rather than through the vent line. If the sealed cap works, then you might consider how to keep critters out of your gas tank. Here's how I did it: Link to comment Share on other sites More sharing options...
Andre Posted June 19, 2021 Share Posted June 19, 2021 The filler neck is huge compared to the vent line, and it goes up where the vent line goes mainly horizontally. So I think the fumes will tend to go out the cap rather than through the vent line. If the sealed cap works, then you might consider how to keep critters out of your gas tank. Here's how I did it: My set up, before I put it all back together, maybe the vent line has to be higher from the valve in the tank. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 19, 2021 Share Posted June 19, 2021 My set up, before I put it all back together, maybe the vent line has to be higher from the valve in the tank. In my experience if the vent line didn't end higher than the top of the fuel fill hose I had fuel vapor smells. That was apparently because the shut off on the hose nozzle at the petrol station filled part way up into the filler hose. So there was fuel above the level of the vent hose. The valve in the tank is supposed to seal, but while mine was new it didn't seal enough. So I had fumes and in some cases liquid fuel coming out. But by getting the vent higher than the filler I no longer have those problems. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted June 19, 2021 Share Posted June 19, 2021 In my experience if the vent line didn't end higher than the top of the fuel fill hose I had fuel vapor smells. That was apparently because the shut off on the hose nozzle at the petrol station filled part way up into the filler hose. So there was fuel above the level of the vent hose. The valve in the tank is supposed to seal, but while mine was new it didn't seal enough. So I had fumes and in some cases liquid fuel coming out. But by getting the vent higher than the filler I no longer have those problems. On my 81 w/300 six the purge vacuum is on the top port of the PVC. Now I did not have any of the parts that would say when it was ok to purge for mine, like that 3 port valve that was shown. So I hooked everything up like it should to the PVC with out the 3 port valve but then had a vacuum leak as it pulled to much vacuum for the canisters. My fix was to install the smallest jet I had from my Holley box in the rubber line and this help control the "leak". I was also getting poor MPG and thinking it was pulling fumes I cut & plugged the vacuum line for testing. I dont think my MPG changed much so I hooked it back up a few weeks back but this time I took a plastic coupling melted the end closed and drilled a much smaller hole in the end so it would restrict the vacuum more and have less of a vacuum leak. So far I do not get a gas smell in my garage other than from a bad fill hose I need to fix one day. Dave ---- Link to comment Share on other sites More sharing options...
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