I just recently replaced one fuel injector that did the same thing (stuck open). Suggest you pull all plugs to determine if all the cylinders are wet with gas or just some of them. If so, first switch the plug to determine if a fouled plug is keeping the cylinder from firing. If not, then replace the injector. You should be able to buy an injector for around $30. They are the same injector as in the US 320i after 1980.