Mk2 golf gti idle/ cutting out issue

[Johnellis]

Hi all, Iv got a fault with my mk2 golf gti. It’s a 1.8 digi. I’ve got an issue with it randomly hunting while idling and now and again when I come to a stop ie dip the clutch it just cuts out. It’s not all the time just now and again. Iv checked for vac leaks and that seems ok, the icv seems to work as it buzzes when the ignitions on and Iv given it a clean too. Iv cleaned the throttle body and replaced the blue ecu coolant temp sensor as it was a non gen so fitted one from Vw. I was told by a friend when replacing the temp sensor to do the procedure where are you unplug it and rev it 3 times bla bla.. but as soon as I unplug it it cuts straight out.
I’v not long serviced it either including replacement of the HT leads and dizi cap and arm. Any help would be muchly appreciated

[kraM]

If it ran OK before you replaced the cap and leads, I'd consider swapping the old ones back over, testing it again.  If it's OK rhythm, start swapping one component at a time, and if it starts misbehaving... Bob's your uncle.