I have a 1987 V12 with Lucas ignition. As I'm driving, or at idle, it feels like the engine is stumbling slightly. I don't know how best to describe it, but it is rhythmic in time with the engine. I suspect that one cylinder isn't firing.
I held a piece of paper up behind the exhaust and the flow from the right side is much stronger than the left, which points be towards the B bank being the problem. All the injectors are clicking, and I put a spark plug tester on the two accessible leads (2B, 3B) and they're good too.

Given the general inaccessibility, I think my next step is to pull the plugs and look at them. My question is, should I do something else first? The plugs and HT leads are six years old with between 4000 and 5000 miles on them.