To add to the wealth of evidence here, which some seem reluctant to acknowledge:
I spent many years away from flying piston engines. When I returned to it, I made it my business to learn all I could, much of which had changed in my absence. Some of it came as a surprise, but a lot of curiosity and an open mind satisfied me that it had merit.
The engine on our single is Bendix fuel injected. It has a fuel pressure sender, which measures pressure, as well as a fuel flow sender, which measures flow. Yes, I know my fuel flow, and no, it's not just pressure expressed differently. The flow meter has been calibrated to be extremely accurate, so if it departs from its normal range we will notice very quickly.
The flow isn't tied directly to pressure, because the pump supplies more than the engine needs. Our fuel pressure goes up significantly when the boost pump is switched on, and so does the flow... briefly. Then the fuel servo adjusts to the new pressure, and the flow goes right back to where it was.
I can, and have, diagnosed a partially blocked injector by means of the engine monitor and the flow gauge. It was obvious which injector was at fault, and the proof was in the contamination later removed from it. Without the monitor, and the training in interpreting it, there would only have been unexplained rough running.
A carbed engine can be run successfully LOP, because I've since done that too. It ran smooth and cool.
Now, I know I'm just a dumb pilot, so I was probably just imagining all the above. But, funny thing, this extended hallucination sure did fit very well with the theory I'd recently been taught.
Isn't learning fun!