Had this vehicle in as a non stater due to ring gear failure

stripped teeth.
Changed flywheel and clutch kit; flywheel Mercedes supply part

number A2660300705. Clutch kit from Valeo part number 826054.
Prior to fitting flywheel was physically checked against

replacement, dowel and cut out all correct.
After refitting vehicle road tested revved above 4000 and driven

approx 4 miles. All OK.
Customer collected car.
Following day customer returned with engine management light

on and drop in performance.
Snap on scanner shows misfire on cylinders 2-3.
Live data shows misfire count rising although no noticeable

misfire apparent count reaches approx 42000 then cuts fueling

to injectors 2-3.
"Misfiring occurs at approx 1700 rpm and initially starts on

number 3 after a short period 2 signals a misfire this rapidly

rises and the 2 remains steady recording no further misfires,

after a further period ,around 50-60-seconds, the misfire register

on 2 clears leaving 3 still counting and injectors off.
On turning off ignition the vehicle will restart with no problems

but with light on. Revving above 1700 will induce the fault.
Of interest is when the scope (picoscope) is connected to

monitor the the crank and/or cam signal the fault does not

present itself.

If the fault is induced and the crank signal peaks 14V occasionally and signal looks erratic. when crank sensor changed it appears the same?