Dont touch the screw, the TCU will automatically adjust any tweaking you do and back it again.
The TPS governs the idle speed via air/fuel mixture. If you believe the idle is low then TPS can be the culprit.
They get sticky with gunk sometimes or the spring can wear.
As far as idle goes, it should be around the 1100-1200 mark on the dash tacho when cold and then settle to about 600-800 after warm up.
Very difficult to know the true RPM because the tacho is not very precise at that end of the dial but just as a rule of thumb it usually looks like its around 1200 at cold start dropping to 700 ish.
If it is the TPS then it may be intermittently sticking.

But you know, lots of possible reasons for die-out, fuel delivery, ignition and engine related.
I recommend you take it to Mal if possible for a diagnosis. He knows these cars.