I don't think its possible for a bad fuel injector to allow fuel to migrate up into the upper plenum area. Sounds like your oil is really gassy and you are sucking it up through the pcv or have a bad turbo seal. You posted earlier about having gas and oil in the turbo inlet, so my guess would be a bad turbo seal and maybe bad fuel injectors or running rich, causing the oil to be gassy. Change the oil asap, Remove the rubber line going from the turbo inlet bell to the valve cover, and put a breather on the v/c. Clean it all up, and if the oil comes back, your turbo is probably smoked. Good time to upgrade!