System Description

Fig. 28 Charcoal Canister Hose Connection, 1978-82 All Models:

The canister has a staged dual feature and four nipples. Two of the nipples are inlets, one for fuel tank vapor and the other for carburetor float bowl vapor. The other two nipples are outlets, one is connected to intake manifold vacuum while the other is for carburetor ported vacuum. When the engine is running, manifold vacuum causes fresh air to enter through the inlet filter in the canister and purge the stored vapor. When ported vacuum increases due to increased throttle opening, the secondary purge circuit is opened and the canister is purged at a much higher rate.