We know "Oil in loom" on TD5s causes running problems.

But oil also can cause running problems in a D2 V8

The D2 V8 suddenly developed a miss and sprung an invisible oil leak, that leaked at the back of the bell housing and onto the Cats to burn off.
Investigated it further today and found the rear valley seal leaking , the oil then coated the ignition coils and plug leads and must have been tracing along the oil. What a mess behind the engine, but not able to be seen with the top part of motor attached.