Not really up on fuel injection, more an old school carby man, but still, sus out the exhaust system for some transient blockage, just to rule that out.
I do understand that temperature senders communicate with f.i. management but how the interface really works I am not sure . If what is happening has ocurred all of a sudden then you can almost bet that a mechanical or electrical component has failed
From what you are describing it seems like some form of mechanical disturbance to timing, maybe ignition, maybe valves, not even sure what engine it is but one thing for sure, I'd be real interested to know your eventual findings, when you reach the end of this, good luck in tracing what it is.
