Hello,

You can test the purge valve by applying vacuum to the top line on the valve (the smallest line). Start the engine (let it idle) and use the vacuum from the PCV port on the manifold. This will open the valve. Then blow (don't suck or else you'll be sucking fuel fumes) into the big line directly beneath the valve. You should be able to blow (indicating the valve is OPENED).

Cut off the vacuum from the small line or just disconnect it from the PCV vacuum port and try to blow again into the big line (beneath the valve). This time you shouldn't be able to blow (indicating the valve is CLOSED).

If you can't blow when vacuum is applied then the valve is damaged. I don't know any way to repair this. The entire canister must be replaced. Visit the FAQ for more info. The canister is made by Rochester (a subsidiary of GM) and you can use any similar canister from GM cars. Or you can get a working similar canister from the junkyard and replace its innards as below.

The line beside the valve (marked TANK) is free flowing to receive fuel fumes from the tank. You can blow into this line all you want (again don't suck - fuel fumes present). The blocked port (marked CARB) functions the same as the TANK, which supposed to receive fuel fumes from carburetor fuel bowl (in cars with carburetors).

I've also replaced the innards of the canister. But to do that you would have pry the cap off (the one with drain hose attached) underneath the canister and break the round plastic grille. There's a felt filter holding small bits of activated charcoal inside. You can easily get these from ebay by ordering similar sizes. About 1lb of charcoal is enough to refill these back. Finish the repair by putting back the felt to hold the charcoal, the plastic grille (just put it back) and push back the cap into place.

The engine only sucks the fuel fumes when throttle is held somewhere along 1500 rpm and above range. The smallest vacuum line just opens into the TB slightly past the throttle plate. Only when the throttle is slightly opened the line becomes active. You can test this by putting a finger on the vacuum port on the TB and open the throttle. If no vacuum is evident then you'd have to clean the port (paper clip and carb cleaner would do).

Don't worry there's no rocket science here : )

Regards,
Amarin.