Engine chucking when hot rev counter pulsing

[oilman241066]

Hi everyone,not been on for a while but looking for any help on this issue,I have a 04 w211 e220 and when my car gets hot( an hours driving)engine sounds as she is missing or "chucking" when I try to go uphill with pedal down,also Rev counter is pulsing when driving at constant speed,like she is getting little surges??
Have replaced fuel rail and fuel pressure sensor and airflow meter but no result to fault,nothing shows with star diagnostic so any help would be appreciated
Thanks

 

[optimusprime]

May be the CPS .But may be the engine is fluctuating in the revs

 

[oilman241066]

Thanks for reply,diagnostics didn't show anything up with cps,but I'd like to know what you mean by engine fluctuating,how can I check this thank you