"In BWV 557 Prelude in G major, the last 2 lines on page 1 have the descending arpeggiated chords spread over 2 octaves shared by the right and left hands. For example, E C G E C G E C, then D B G D B G D B.
I am having real trouble trying to play these without looking at my fingers, even at a slow pace. In fact, even slowing down to a very slow pace, it seems more like luck if I get it right or not. If I regularly just glance down its OK (like once or twice a measure), and if I watch my fingers the whole time its quite easy and I can play faster.
How do I get my fingers to the right places every time without checking I’m starting on the right note? I think this is my poor manual technique catching up with me!
What has surprised me is how quickly and easily I picked up the pedal solo this time, it was very encouraging!"
Another technique which helps is transposition of these arpeggios. But don't start transposing to other keys right away. Instead, try to analyse the arpeggios mentally and understand what kind of chords they comprise. For example, in the above case, E-C-G-E-C-G-E-C is a C major root position chord and D-B-G-D-B-G-D-B is G major 1st inversion chord.
Even better, you can identify each note not only as belonging to a particular chord but being a certain scale degree in this key (G major). For example, these two arpeggios would consist of 6-4-1-6-4-1-6-4 and 5-3-1-5-3-1-5-3. Naturally these chords are the subdominant chord (C major) and tonic 6th chord (G major).
Since scale degrees really help "to translate" the music you are playing, I am pretty sure that playing them without looking at the fingers will become for you much easier as well.