bigbreak_2000 Posted June 8, 2013 Share Posted June 8, 2013 The the car stands in the garage it smells fuel for days on end. I've checked for gas line leaks but nothing. The OEM gas cap also seems to be in good condition. I suspect there is an issue with missing connections on the charcoal canister however with the distributor I'm using, and intake system the is no connections points to get a distr advance signal or to run a purge line back into the intake. (the engine is modified with ITBs and is EFI) If the car is not running, is it possible the fume from the tank breath straight through the canistor into atmosphere? I thought there is a valve in the canister thats suppose to hold the fumes so they cannot pass through the purge valve unless there is a vacuum signal from the distributor...Regardless my weak understanding how it works, can someone give me an idea on how to setup a functional charcoal canister for an engine that does not have a distr vacuum switch and used a modified intake system? I have the one line that comes from the tank and connects into the canistor. Right now the other 2 lines on the canistor, one for distr vacuum signal is open ended, and the purge line is also open ended. One thought I had was to install a swith that runs off the MSD box (thats activates at say 2000rpms) and have than connected to a electrical purge valve, as they have on Fords/Volvos. Then I would just run the purge line from the canister, through this purge valve, to the filter element so that when the motor is running above 2000rpms the valve would open and allow the fume out of the canistor. With the location of the open end of the purge line right by the intake filter the fumes would be sucked right into the motor. Would that not work? Quote Link to comment Share on other sites More sharing options...
johnc Posted June 8, 2013 Share Posted June 8, 2013 You still need to vent the tank even with the engine off. Changes in ambient temperature cause pressure changes in the tank. I suggest you modify your intake to allow reconnection of the stock system. You might also open up the canister and wash the interal filtering media. It's probably saturated with fuel. Quote Link to comment Share on other sites More sharing options...
bigbreak_2000 Posted June 8, 2013 Author Share Posted June 8, 2013 john, what do I do with the hose that in the stock setup was connected to the distr vacuum switch? Quote Link to comment Share on other sites More sharing options...
bigbreak_2000 Posted June 8, 2013 Author Share Posted June 8, 2013 the PO had the one hose of the canister connected to the vacuum control valve on the distributor, on my setup the distributor does not have a vacuum control valve. Perhaps the PO had it wrongly connected but that is why I am now not certain what to do with the one hose that is suppose to connect to the canister. the purge hose I can still connect somehow to the intake box which is a fibreglass box Quote Link to comment Share on other sites More sharing options...
bigbreak_2000 Posted June 8, 2013 Author Share Posted June 8, 2013 the hose I am puzzled to where it needs to connects to is described in the FSM as "to throttle chamber (ported vacuum)". per the diagram it appears to connect to the throttlebody, at a location pre-tb plate. So I'm assuming this hose can connect to any point in the intake system between the airfilter and the tb's. The purge hose though has to connect to the manifold runners after the tb's. So perhaps the purge hose can be T'd to either the brake booster vacuum hose or the vacuum hose to the MAP sensor. Does this sound right? Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 9, 2013 Share Posted June 9, 2013 Where the hell did my post go? Not again on an iPad, sorry! Quote Link to comment Share on other sites More sharing options...
bigbreak_2000 Posted June 27, 2013 Author Share Posted June 27, 2013 Tony, can you try and repost your response please? I'm still without ideas. The intake does not have another boss for a purge line. I could add a manifold vacuum which will give me a couple more connection but then I also don't know where to pull ported vacuum from. Someone else told me the old vw beetles did not have a charcoal canister but the tank fumes ran into some kind of filter which breathed open , I'm nut sure what kind of filter would remove the fumes... Quote Link to comment Share on other sites More sharing options...
socorob Posted June 27, 2013 Share Posted June 27, 2013 The old cars didn't have any emission regulations to deal with so the fumes were just vented to the atmosphere. They would come out of the carbs and a lot of cars back in the day had vented gas caps. That's why sometimes at the autocrosses you'll see some of the old British cars having gas come out of the caps on hard turns if their tanks are too full. Not a good thing. Quote Link to comment Share on other sites More sharing options...
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