Does the line you put to it have vacuum? It shouldn't be dumping fuel unless there is zero vaccum applied (wot) or the diaphragm is broken (it would have fuel coming out of it by unplugging the vacuum line). The injectors continuing to fire after the engine isn't running is making me think it may be the computer. Crank it till it stops, the pull the plugs out and see if you are actually hydro locking. Does the oil have fuel in it?