Hi Jgor–
Can you play the “Yngwie 6” one string pattern up to speed using legato or just picking the first note of each 6 and keep it in time? If your fret hand timing is off you will not be able to sync up the pick hand no matter what.
Can you play the pattern legato for 30 seconds or so at 140 and keep it in time?
I know for me sometimes the issue is/was in the fret hand–so no matter how much “hammering away” I did with the pick hand it was never going to sync up because the fret hand was off.
My apologies if this was already suggested or you have already tried it.