Those throttle stop screws shouldn't really be messed with as they're set to a point that the ECU knows as throttle shut and needs specialist info and often equipment to reset.
Could be worth giving the throttle body inners a good clean as they gum up and don't fully close or let less air through.
Just got back from the Isle of Wight. Totally boring route home along dual carriage way and motorway but only took me 4 hours and 1 fill up after crossing the wet stuff.
Line up wasn't that good this year but still enjoyed.
Made it to the isle of wight’ got to daughters at about 5.30 where a pint of squash and a glass of rose was placed in each hand.
travelled via the A12 which was mostly overcast. Soon got hotter going west on the M25. It’s bloody roasting here now.