Hello James,
How did you go? still with CX 7 or you torched?
I have same problems

Most likely your injector is plugged and is leaking. Did you check if there is a pressure drop in the rail.

The other option is the high-pressure pump is leaking fuel into the engine.
Both can be fixed. Narazie

Dziekuje for ideas! I will do recondition of injectors first and than pump :-) I had also turbo leaking oil but thanks to your suggestion it all make sense as there is a lot of fuel in oil and oil is too thin... so go through turbo!
Dziekuje! I will update you with results!

I had the same issue I changed the fuel filter and the spark plug runs fine now it is back to normal