Fuel Tank Vent Valve
 

I got a 91 E Class with 102 engine (2 liter petrol). I thought my tank pressure was high so I checked the vent valve under the rear suspension. I took it out and cleaned it and it seems to work ok - hold some pressure in the tank but air passes in easily if vacuum in tank. However it looks like the diesel type vent to atmospshere type (with protective rubber boot and all) with no line going to a charcoal canister in the engine bay. In the engine bay I see the vacuum solenoid with vacuum line going somewhere. Can anyone explain?