as we all know DTs have an constant issue on electricity/wireing/fuses etc. The comment above are TOP to diagnose it.
Well I was more nervous on the INSTRUMET reading quality itself - after obejing the above instructions from the team . I love Italia..is just 450 km form here.
So as above (when you have found the issue on probably electrical nature) I recommend something like this "EXPERIMENTAL" set up.
readings at idle for brand new motor app. 800/750 up/m
Cold 10/40 oil = 4..5 ATM
Hot = 2 ATM !!!
Use correct Temp and pressure material tube ok ! I will have the instument moved to the rear window or have a nice spot in the engine bay.